Merge pull request '[READY][Gameplay] #310 Host transition idempotency and error catalog for scoreboard -> next round / finish' (#320) from dev/issue-310-host-transition-idempotency-v2 into main

Reviewed-on: #320
Reviewed-by: reviewer-bot <review-no-reply@weircon.dk>

.claude/settings.json

@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash"
+    ]
+  }
+}

.gitea/workflows/ci.yml

@@ -31,3 +31,17 @@ jobs:
 
       - name: Tests
         run: python manage.py test lobby -v 1
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+
+      - name: Install SPA dependencies
+        run: |
+          npm ci --prefix frontend/angular
+          node -e "require('./frontend/angular/node_modules/rollup/dist/native.js')" \
+            || npm install --prefix frontend/angular
+
+      - name: SPA Angular smoke tests
+        run: npm --prefix frontend/angular test

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [Unreleased]
+### Docs
+- Added `docs/ISSUE-279-I18N-MVP-CLOSEOUT.md` with the issue #279 i18n MVP close-out note, including migration impact, reusable release-note text, and a release-readiness checklist refreshed against `main@1bc4c27` after PR #282/#283 landed on 2026-03-13 UTC.
+- Clarified that the close-out note supersedes earlier PR snapshot assumptions and now treats PR #282 (`6ad5430`) and PR #283 (`1bc4c27`) as already merged on `main`.
+
 ## [0.1.0] - 2026-02-27
 ### Added
 - Projekt scaffold for Weirsøe Party Protocol (Django 6.0.2)

CLAUDE.md

@@ -0,0 +1,119 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+**Weirsøe Party Protocol** is a Danish party game web platform (Jackbox-style) where games display on a primary screen and players participate via mobile. The MVP game is "Fup og Fakta" (a Fibbage-style lie-and-guess game).
+
+- Backend: Django 6.0.2 + Django Channels (WebSockets) + Redis
+- Frontend: Angular 19 shell + shared TypeScript API client library
+- Database: MySQL (SQLite fallback for dev)
+- Deployment: Proxmox LXC containers (not Docker)
+
+## Commands
+
+### Backend (Django)
+```bash
+python manage.py runserver       # Dev server
+python manage.py migrate         # Apply migrations
+python manage.py test            # Run all backend tests
+python manage.py test lobby      # Run tests for a single app
+python manage.py shell           # Django shell
+```
+
+### Frontend — API client (`/frontend`)
+```bash
+cd frontend
+npm install
+npm test       # Vitest unit tests
+npm run build  # TypeScript compile check (--noEmit)
+```
+
+### Frontend — Angular shell (`/frontend/angular`)
+```bash
+cd frontend/angular
+npm install
+npm start      # Dev server (ng serve)
+npm run build  # Production build
+npm run test   # Vitest unit tests
+```
+
+### i18n validation
+```bash
+python scripts/check_i18n_drift.py   # Check for key drift between locales
+```
+
+## Architecture
+
+### Backend apps
+
+| App | Purpose |
+|-----|---------|
+| `partyhub/` | Main Django project — settings, root URLs, ASGI/WSGI, i18n bootstrap |
+| `lobby/` | Session & player management — create/join session, locale-aware error responses |
+| `fupogfakta/` | Game logic — all domain models, score calculation (server-authoritative) |
+| `realtime/` | WebSocket event layer (stub) |
+| `voice/` | Voice/TTS interface (stub, Phase 2) |
+| `core_admin/` | Health endpoint (`/healthz`), global admin |
+
+**Key domain models** (all in `fupogfakta/models.py`): `GameSession`, `Player`, `Category`, `Question`, `RoundConfig`, `RoundQuestion`, `LieAnswer`, `Guess`, `ScoreEvent`.
+
+Score calculation is server-side only. `ScoreEvent` provides an auditable trail of all point changes.
+
+### Frontend layers
+
+1. **Shared API client** (`frontend/src/`) — pure TypeScript, framework-agnostic. Defines all API types (`api/types.ts`) and HTTP client abstraction (`api/client.ts`).
+2. **Angular shell** (`frontend/angular/`) — Angular 19 standalone components (no NgModules), hash-based routing. `host-shell.component` for the presenter screen; `player-shell.component` for mobile players.
+
+The Angular shell consumes the shared client via `frontend/src/api/angular-client.ts`.
+
+### Real-time flow
+
+`LOBBY → LIE → GUESS → REVEAL → FINISHED` — phase transitions broadcast a `PhaseViewModel` to all connected clients via WebSocket. Clients are read-only; only the server is authoritative for state.
+
+### i18n
+
+- **Single source of truth**: `shared/i18n/lobby.json` (keys in both `en` and `da`)
+- Loaded once at startup with LRU cache (`partyhub/i18n_bootstrap.py`)
+- Key naming: domain-first — `frontend.ui.host.*`, `frontend.ui.player.*`, `backend.errors.*`, `backend.error_codes.*`
+- Locale resolved from `Accept-Language` header; missing key returns key + logs warning; missing translation falls back to `en`
+
+## Key Conventions
+
+### Errors
+Backend error responses use stable machine-readable codes (`backend.error_codes.*`) with separately localized messages. Never couple error code strings to locale.
+
+### Game constraints (MVP)
+- 3–12 players per session
+- Session codes: 6-char alphanumeric (no 0/O/1/I/L)
+- Anti-cheat: no duplicate lies, lies cannot match the correct answer, answer order randomized
+
+### Git workflow
+- `main`: stable baseline
+- `feature/<name>`: development branches
+- `release/vX.Y.Z`: release preparation
+- Release: merge → create release branch → update `VERSION` + `CHANGELOG.md` → tag → push
+
+### TypeScript
+Strict mode required. Target ES2022. API response interfaces in `frontend/src/api/types.ts` must match backend responses exactly.
+
+### Database
+Use `ForeignKey` with explicit `on_delete` (`PROTECT`/`CASCADE`/`SET_NULL`). Add `db_index=True` on frequently queried fields. Migrations are auto-generated by Django and versioned in `migrations/`.
+
+## Environment Variables
+
+```
+DJANGO_SECRET_KEY, DJANGO_DEBUG, DJANGO_ALLOWED_HOSTS
+DB_ENGINE, DB_NAME, DB_USER, DB_PASSWORD, DB_HOST, DB_PORT
+CHANNEL_REDIS_HOST, CHANNEL_REDIS_PORT
+USE_SPA_UI (fallback: WPP_SPA_ENABLED)
+WPP_SPA_ASSET_BASE, WPP_SPA_ASSET_VERSION
+```
+
+## Test Files of Note
+
+- `lobby/tests.py` — comprehensive Django TestCase coverage for session/player/i18n/error flows
+- `frontend/angular/src/app/api-contract-smoke.spec.ts` — API contract smoke tests
+- `frontend/angular/src/app/lobby-i18n.spec.ts` — i18n parity checks
+- `frontend/tests/lobby-loader.parity.test.ts` — shared i18n loader parity

PROMPT.md

@@ -0,0 +1,71 @@
+# Ralph Loop: Implement WebSocket push for Weirsøe Party Protocol
+
+## Context
+- Project: /home/agw/projects/weirsoe-party-protocol
+- Backend: Django 6.0.2 + Django Channels + Redis
+- The full game REST flow is already implemented in lobby/views.py
+  (create_session, join_session, start_round, show_question, submit_lie,
+  mix_answers, submit_guess, calculate_scores, reveal_scoreboard, finish_game)
+- realtime/ app exists but is a stub (no consumers.py, no routing)
+- partyhub/settings.py has channels in INSTALLED_APPS but no CHANNEL_LAYERS or routing
+- PO hard requirement: WebSocket push is mandatory in MVP (no polling)
+
+## What to build
+
+### 1. realtime/consumers.py — GameConsumer
+- AsyncJsonWebsocketConsumer
+- Connects to group game_{session_code} on connect (session_code from URL)
+- Player auth: session_token query param validated against Player model
+- Host auth: query param role=host, no token required for MVP
+- On disconnect: clean leave from group
+- Handles incoming message type "ping" -> replies with {"type": "pong"}
+- Forwards broadcast group events to WebSocket client
+
+### 2. partyhub/settings.py — CHANNEL_LAYERS
+Add CHANNEL_LAYERS using channels_redis.core.RedisChannelLayer.
+Read CHANNEL_REDIS_HOST (default 127.0.0.1) and CHANNEL_REDIS_PORT (default 6379) from env.
+
+### 3. partyhub/asgi.py — ASGI routing
+Wire URLRouter so ws/game/<session_code>/ routes to GameConsumer.
+Keep existing HTTP routing intact.
+
+### 4. realtime/routing.py
+Define websocket_urlpatterns list.
+
+### 5. realtime/broadcast.py — broadcast helper
+- async def broadcast_phase_event(session_code, event_type, payload)
+  Sends to group game_{session_code} via channel layer.
+- def sync_broadcast_phase_event(session_code, event_type, payload)
+  Sync wrapper using async_to_sync for calling from sync REST views.
+
+### 6. lobby/views.py — hook broadcasts into phase transitions
+After each phase transition, call sync_broadcast_phase_event:
+- start_round      -> phase.lie_started   (question prompt + time limit)
+- show_question    -> phase.question_shown (question text)
+- mix_answers      -> phase.guess_started  (shuffled answers + time limit)
+- calculate_scores -> phase.scores_calculated (per-player score delta)
+- reveal_scoreboard -> phase.scoreboard   (ranked player list)
+- finish_game      -> phase.game_over     (final rankings)
+
+### 7. realtime/tests.py — basic tests
+- Connect/disconnect test using channels.testing.WebsocketCommunicator
+- Verify a broadcast reaches a connected client
+
+## Constraints
+- Keep auth simple: session_token query param for players, unauthenticated host in MVP
+- Use async_to_sync wrapper for sync REST views calling async broadcast
+- Do not break existing REST tests (python manage.py test lobby must still pass)
+- After each file written, run: python manage.py check
+- Follow existing code style in lobby/views.py
+
+## Completion criteria
+Output the exact text: WEBSOCKET COMPLETE
+
+...when ALL of the following are true:
+- realtime/consumers.py exists and handles connect/disconnect/ping
+- realtime/broadcast.py exists with sync_broadcast_phase_event
+- partyhub/settings.py has CHANNEL_LAYERS configured
+- partyhub/asgi.py routes ws/game/<code>/ to GameConsumer
+- All 6 phase transitions in lobby/views.py call sync_broadcast_phase_event
+- python manage.py check passes with no errors
+- python manage.py test lobby passes (existing tests not broken)

TODO.md

@@ -37,8 +37,8 @@ Byg **Weirsøe Party Protocol**: en dansk party-webapp platform ala Jackbox, hvo
   - [x] `core_admin` (global administration)
   - [x] `fupogfakta` (Spil 1)
   - [x] `lobby` (room/session/player join flow)
-  - [x] `realtime` (channels events, game state broadcast)
-  - [x] `voice` (fælles voice-acting interface)
+  - [x] `realtime` (app-skelet oprettet — consumers/routing IKKE implementeret endnu)
+  - [x] `voice` (fælles voice-acting interface — stub)
 - [x] Miljøfiler (`.env.test`, `.env.prod` skabeloner)
 - [x] Konfig for MySQL test/prod
 
@@ -53,14 +53,15 @@ Byg **Weirsøe Party Protocol**: en dansk party-webapp platform ala Jackbox, hvo
 - [x] `ScoreEvent` (auditérbar pointslog)
 
 ### Fase 3 — Spilflow `Fup og Fakta`
-- [x] Lobby: host opretter session, spillere joiner via kode
-- [x] Runde starter med kategori
-- [x] Spørgsmål vises -> alle skriver løgn inden X sek
-- [x] System blander korrekt svar + løgne
-- [x] Guessfase: alle gætter inden Z sek
-- [x] Pointudregning (konfigurerbar pr. runde)
-- [x] Scoreboard + næste spørgsmål/runde
-- [x] Slutresultat
+- [x] Lobby: host opretter session, spillere joiner via kode (REST)
+- [x] Runde starter med kategori (REST)
+- [x] Spørgsmål vises -> alle skriver løgn inden X sek (REST)
+- [x] System blander korrekt svar + løgne (persisted i JSONField, anti-cheat dedup)
+- [x] Guessfase: alle gætter inden Z sek (REST)
+- [x] Pointudregning (konfigurerbar pr. runde, ScoreEvent audit trail)
+- [x] Scoreboard + næste spørgsmål/runde (REST)
+- [x] Slutresultat (REST)
+- [x] **WebSocket push af phase-events til host + spillere** (GameConsumer + broadcast.py, InMemoryChannelLayer i tests)
 
 ### Fase 4 — Voice-acting (platformkrav)
 - [ ] Definér TTS provider-interface
@@ -103,10 +104,11 @@ Byg **Weirsøe Party Protocol**: en dansk party-webapp platform ala Jackbox, hvo
 - [ ] Migrations + static + health checks
 
 ### Backlog — Need-to-have / Nice-to-have
-- [ ] (Need-to-have) Persistér mixed svarrækkefølge pr. round question, så alle spillere ser samme rækkefølge ved reconnect/refresh
+- [x] (Need-to-have) Persistér mixed svarrækkefølge pr. round question — DONE (JSONField + migration 0003 + test)
 - [x] (Need-to-have) Tilføj spiller-auth/session-token for submit_lie (pt. baseret på player_id i payload)
 - [ ] (Nice-to-have) Endpoint til status/progress i løgnfasen (antal indsendt ud af total)
-- [ ] (Need-to-have) [Fejltype: CI/lint F401] [Fil/område: core_admin/*, fupogfakta/tests.py+views.py, lobby/admin.py+models.py, realtime/*, voice/*] [Branch/PR: feature/f3-lobby-create-join, feature/fase0-mvp-fup-og-fakta, feature/lobby-mvp (ingen åbne PRs fundet)] Fjern ubrugte scaffold-imports (eller kør ruff check --fix) så quality gate kan blive grøn før merge.
+- [ ] (Need-to-have) Fjern ubrugte scaffold-imports i core_admin/*, realtime/*, voice/*, fupogfakta/views.py (kør `ruff check --fix`) så CI quality gate er grøn
+- [x] (Need-to-have) [Issue #251] Release-often lane: SPA MVP opdelt i 3 merge-klare micro-PR batches (plan + acceptance criteria dokumenteret i `docs/ISSUE-251-RELEASE-OFTEN-SPA-MVP-BATCH-PLAN.md`).
 - [ ] (Need-to-have) Rate limiting på join/submit endpoints
 - [ ] (Need-to-have) Session-kode brute-force beskyttelse
 - [ ] (Need-to-have) Audit-log for host-handlinger (start/stop/skip)

docs/I18N_ARCHITECTURE.md

@@ -0,0 +1,49 @@
+# Shared i18n architecture (frontend + backend)
+
+## Scope
+Issue #175 requires one shared i18n contract for MVP host/player flows across frontend and backend.
+
+## Source of truth
+- Catalog: `shared/i18n/lobby.json`
+- Locales:
+  - supported: `en`, `da`
+  - default/fallback: `en`
+
+Django (`lobby/i18n.py`) reads directly from the catalog. Frontend runtimes are Angular-first and use a shared loader (`frontend/shared/i18n/lobby-loader.ts`) so Angular shell and SPA fallback consume the same keyspace + locale normalization.
+
+## Key naming convention
+- Domain-first namespaces:
+  - `frontend.ui.common.*`
+  - `frontend.ui.host.*`
+  - `frontend.ui.player.*`
+  - `frontend.errors.*`
+  - `backend.errors.*`
+  - `backend.error_codes.*`
+- UI lookup keys in Angular are shortened aliases mapped under `frontend.ui`, e.g.:
+  - `host.start_round`
+  - `player.submit_guess`
+  - `common.session_code`
+- Backend API errors return stable code + localized message:
+  - `error_code` = machine-stable key from `backend.error_codes`
+  - `error` = localized message from `backend.errors`
+  - `locale` = resolved request locale
+
+## Fallback model (robust)
+1. Resolve requested locale (`Accept-Language` on backend, user/browser preference on frontend).
+2. If locale unsupported -> use default `en`.
+3. If key missing -> return key and log warning.
+4. If locale translation missing for key -> fallback to `en` translation.
+
+## Audio-routing policy
+- Catalog capability: `frontend.capabilities.client_has_no_audio_output = true`
+- Host/player clients expose this as a read-only capability flag.
+- Policy: phone clients must not play audio directly; only primary/host output is allowed.
+
+## Verification
+- Backend tests: `lobby/tests.py` i18n coverage for locale selection + fallback + error-code/message matrix.
+- Frontend smoke/e2e-level unit coverage:
+  - `frontend/angular/src/app/lobby-i18n.spec.ts`
+  - `frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts`
+  - `frontend/angular/src/app/features/host/host-shell.component.spec.ts`
+  - `frontend/angular/src/app/features/player/player-shell.component.spec.ts`
+  - `frontend/tests/lobby-loader.parity.test.ts` (minimal da/en key parity guard for shared keyspace)

docs/ISSUE-175-I18N-SHARED-CONTRACT-ARTIFACT.md

@@ -0,0 +1,35 @@
+# ISSUE-175 Artifact — shared i18n contract + MVP host/player flow
+
+## Delivered
+- Shared i18n contract is centralized in `shared/i18n/lobby.json` (da/en, default `en`, robust fallback).
+- Frontend host/player MVP copy is read via shared keys (no hardcoded Danish strings in Angular MVP flow components).
+- Backend error messages resolve from shared keyspace with locale-aware API payload (`error_code`, `error`, `locale`).
+- Audio-routing policy is explicit and shared: `frontend.capabilities.client_has_no_audio_output=true`.
+- Architecture + key naming documented in `docs/I18N_ARCHITECTURE.md`.
+
+## Smoke / e2e evidence
+### Backend locale + fallback
+Command:
+```bash
+. .venv/bin/activate && python manage.py test \
+  lobby.tests.LobbyFlowTests.test_join_error_localizes_to_danish_with_accept_language_header \
+  lobby.tests.LobbyFlowTests.test_join_error_falls_back_to_english_for_unsupported_locale \
+  lobby.tests.I18nResolverTests
+```
+Result:
+- PASS (7 tests)
+- Confirms `da` localization and fallback to `en` for unsupported locale.
+
+### Frontend host/player + language switch + audio policy
+Command:
+```bash
+cd frontend/angular
+npm test -- --run \
+  src/app/lobby-i18n.spec.ts \
+  src/app/i18n-mvp-flow-smoke.spec.ts \
+  src/app/features/host/host-shell.component.spec.ts \
+  src/app/features/player/player-shell.component.spec.ts
+```
+Result:
+- PASS (22 tests)
+- Includes smoke for host/player copy in **both en and da** and verifies primary-only audio policy flag (`clientHasNoAudioOutput=true`).

docs/ISSUE-188-SPA-CUTOVER-HARDENING-ARTIFACT.md

@@ -0,0 +1,47 @@
+# Issue #188 Artifact — SPA cutover hardening (asset versioning + rollback)
+
+## Scope
+Acceptance for `[READY][SPA][P11] Cutover hardening`:
+1. Dokumenteret strategi for cache-busting/versionering af SPA assets i Django staticfiles/reverse proxy setup.
+2. Konfigurerbar rollback-procedure for `USE_SPA_UI` (trin-for-trin, target <10 min).
+3. Smoke-artefakt for både SPA on/off i samme release-vindue.
+4. Ingen gameplay-ændringer.
+
+## 1) Asset versioning/cache-busting strategi
+Implementeret i SPA shell render-path:
+
+- Konfiguration i `partyhub/settings.py`:
+  - `WPP_SPA_ASSET_BASE` (eksisterende)
+  - `WPP_SPA_ASSET_VERSION` (ny)
+- `lobby/ui_views.py` injicerer `spa_asset_version` til template-context.
+- `lobby/templates/lobby/spa_shell.html` appender `?v={{ spa_asset_version }}` på:
+  - `styles.css`
+  - `main.js`
+
+Effekt:
+- Ny release-version (fx SHA/tag) kan tvinge cache-miss i browser/proxy uden ændring af route.
+- Rollback kan pege på tidligere stabil version-token med samme mekanisme.
+
+## 2) Rollback playbook (`USE_SPA_UI`) — target <10 min
+Dokumenteret i `docs/spa-cutover-flag.md`:
+
+1. Sæt `USE_SPA_UI=false`.
+2. Sæt `WPP_SPA_ASSET_VERSION` til sidste stabile release-token.
+3. Deploy/reload app-processer.
+4. Verificér legacy routes (`/lobby/ui/host` + `/lobby/ui/player`).
+5. Kør hurtig smoke sanity.
+6. Log trigger/timestamp/resultat i smoke artifact.
+
+## 3) Smoke artifact for SPA OFF/ON i samme release-vindue
+Dokumenteret i:
+- `docs/UI_SMOKE.md` (sektion: "Samme release-vindue: SPA OFF + ON verifikation")
+- `docs/STAGING_GAMEPLAY_SMOKE_ARTIFACT.md` (template udvidet med release-window check + `WPP_SPA_ASSET_VERSION`)
+
+Krav:
+- OFF-pass (legacy) og ON-pass (SPA) køres i samme deploy/release-vindue.
+- Begge passes logges i samme artifact med UTC timestamps og version-token.
+
+## Non-goals bekræftet
+- Ingen gameplay-regler ændret.
+- Ingen API-kontrakter ændret.
+- Ingen UX-redesign; kun drift/cutover-hardening.

docs/ISSUE-200-SPA-HOST-PLAYER-PHASE-SYNC-ARTIFACT.md

@@ -0,0 +1,57 @@
+# Issue #200 Artifact — SPA host→player phase sync (no reload)
+
+## Scope
+Acceptance for `[READY][SPA][P14] Gameplay MVP-del 5`:
+1. Host handlinger (`start round` / `næste fase`) propagere korrekt til player-ruter i SPA.
+2. Happy-path artefakt for én fuld faseovergang uden page reload.
+3. Sync-fejl giver kontrolleret fallback/error state.
+
+Afgrænsning overholdt: ingen nye spilregler og ingen redesign af backend event-model.
+
+## Happy-path faseovergang (uden page reload)
+Reference-flow i Angular shell:
+
+1. **Host starter runde/fase**
+   - Host action kalder backend endpoint (`POST /lobby/sessions/:code/start` eller fase-endpoint)
+   - Host shell hydrerer session igen (`GET /lobby/sessions/:code`)
+   - Host route synkes via hash-rewrite i samme SPA shell:
+     - `#/host/<phase>/<CODE>`
+     - Implementeret i `HostShellComponent.syncRouteFromSession()`
+
+2. **Player modtager ny fase via state sync**
+   - Player shell kører periodisk session-refresh (3s), uden hard reload
+   - Når `session.status` ændrer sig, synkes hash-route i samme SPA shell:
+     - `#/player/<phase>/<CODE>`
+     - Implementeret i `PlayerShellComponent.syncRouteFromSession()`
+
+3. **Ingen page reload**
+   - Routing sker med `window.history.replaceState(...)`
+   - URL opdateres i eksisterende SPA instans (ingen template-hop, ingen full refresh)
+
+## Kontrolleret fallback ved sync-fejl
+Når player-sync fejler (netværk/fetch/session-refresh):
+
+- UI går i kontrolleret connection-state:
+  - `reconnecting` ved online netværksfejl
+  - `offline` når browser rapporterer offline
+- Fejl vises med retry/back-to-join handlinger
+- Reconnect forsøges igen via timer (`scheduleReconnect`) uden at crashe shell
+
+## Verifikation (tests)
+Kørt i `frontend/angular` med Vitest:
+
+- `src/app/features/host/host-shell.component.spec.ts`
+  - Verificerer host-faseflow og hash-route sync uden reload
+- `src/app/features/player/player-shell.component.spec.ts`
+  - Verificerer periodisk player state sync + hash-route sync
+  - Verificerer reconnect/offline fallback ved sync-fejl
+- `src/app/api-contract-smoke.spec.ts`
+- `src/app/session-route-context.spec.ts`
+
+Kommando:
+
+```bash
+npm test -- --reporter=dot
+```
+
+Resultat: **4/4 testfiler grønne, 22/22 tests bestået**.

docs/ISSUE-205-I18N-FOUNDATION.md

@@ -0,0 +1,36 @@
+# Issue #205 — Django i18n foundation (da/en)
+
+## Implemented acceptance checks
+
+- **Django i18n setup for `en` + `da` with `en` fallback**
+  - `LANGUAGE_CODE` set to `en`.
+  - `LANGUAGES = [('en', 'English'), ('da', 'Danish')]`.
+  - `LocaleMiddleware` enabled in middleware chain.
+- **Shared-key resolver/adapter (no ad hoc backend mapping)**
+  - Backend error responses now resolve from shared catalog keys in `shared/i18n/lobby.json`.
+  - `lobby.i18n.api_error()` accepts a shared key and resolves locale-specific text.
+- **Representative API flow documented with key/locale behavior**
+  - `POST /lobby/join` with empty code returns:
+    - `error_code: "session_code_required"`
+    - localized `error`
+    - resolved `locale`
+- **Missing key handling deterministic and loggable**
+  - `resolve_error_message()` returns key string when key/translation is missing.
+  - Warning is logged (`lobby.i18n` logger) for missing key/translation.
+
+## Example response behavior
+
+### Request
+`POST /lobby/join` with empty code and header `Accept-Language: da`
+
+### Response (400)
+
+```json
+{
+  "error": "Sessionskode er påkrævet",
+  "error_code": "session_code_required",
+  "locale": "da"
+}
+```
+
+If locale is unsupported (e.g. `fr`), response uses `locale: "en"` and English message.

docs/ISSUE-207-I18N-AUDIO-SMOKE-ARTIFACT.md

@@ -0,0 +1,35 @@
+# Issue #207 Artifact — da/en locale switch + audio routing (primary-only)
+
+## Scope
+Acceptance for `[READY][i18n][P19]`:
+1. Verify one MVP host+player flow in both `en` and `da` locale context.
+2. Verify controlled fallback to `en` when a locale key is missing.
+3. Verify audio-routing policy is primary-only (client/player has no audio output).
+
+No new feature behavior added — this is verification-only evidence.
+
+## Smoke/e2e evidence (Angular shell test run)
+Executed from `frontend/angular`:
+
+```bash
+npm test -- --reporter=dot src/app/lobby-i18n.spec.ts src/app/features/host/host-shell.component.spec.ts src/app/features/player/player-shell.component.spec.ts
+```
+
+Evidence covered by the run:
+- `lobby-i18n.spec.ts`
+  - subscriber locale switch updates (`en -> da -> en`)
+  - controlled fallback where `da` key is removed during test and `en` copy is returned
+  - `clientHasNoAudioOutput === true` (primary-only audio routing)
+- `host-shell.component.spec.ts`
+  - host actions and route sync in SPA (no reload)
+- `player-shell.component.spec.ts`
+  - player session refresh/sync path and retry behavior
+
+## Policy evidence
+- Shared catalog capability: `shared/i18n/lobby.json`
+  - `frontend.capabilities.client_has_no_audio_output = true`
+- Angular host/player shells bind this capability:
+  - `HostShellComponent.clientHasNoAudioOutput`
+  - `PlayerShellComponent.clientHasNoAudioOutput`
+
+Conclusion: locale switching works in `da`/`en`, fallback resolves to `en` when locale key is intentionally missing, and client audio remains disabled by policy (`primary-only`).

docs/ISSUE-223-PLAYER-AUDIO-GUARD-ARTIFACT.md

@@ -0,0 +1,20 @@
+# Issue #223 — Telefon-klient audio guard (artifact)
+
+## Scope leveret
+- Telefon-/player-klient installerer en eksplicit audio guard ved mount (`installSecondaryDeviceAudioGuard`).
+- Guard overskriver `HTMLMediaElement.prototype.play` til en no-op på secondary device (client policy: `client_has_no_audio_output=true`).
+- Guard fjernes igen ved unmount (`ngOnDestroy`) så øvrige flows/enheder ikke påvirkes.
+- Ingen audio-controls er eksponeret i player-shell UI.
+
+## Acceptance mapping
+1. **Telefon-klient trigger ikke audio playback i kerneflow**
+   - Verificeret af test: `player-shell.component.spec.ts` (`installs secondary-device audio guard while player shell is mounted`).
+2. **Primær enhed påvirkes ikke negativt**
+   - Guard er scoped til player-shell lifecycle og restore'r original `play` ved destroy.
+3. **Enkel test/verifikation dokumenteret**
+   - Dokumenteret her + testkørsel nedenfor.
+
+## Testkørsel
+- Kommando:
+  - `cd frontend/angular && npm test -- src/app/features/player/player-shell.component.spec.ts`
+- Resultat: bestået (inkl. audio-guard test).

docs/ISSUE-224-TRUNK-SEQUENCE-175.md

@@ -0,0 +1,55 @@
+# Issue #224 — Trunk-sekvens for #175 (A/B/C)
+
+Formål: gøre #175 scheduler-klar som tre små, uafhængige og mergeklare bidder.
+
+## Sekvens
+
+### A) Backend i18n baseline
+- Tracking issue: #225
+- Scope:
+  - Backend resolver til locale (da/en)
+  - Fallback til `en` ved unsupported locale
+  - Stabil fejlkontrakt i payload (`error_code`, `error`, `locale`)
+- Mergebarhed: Kan merges uden frontend-ændringer.
+- Acceptance:
+  - Backend tests dækker `da` + fallback `en`
+  - Kontraktfelter er stabile i response
+
+### B) Shared key-map + locale-kontrakt
+- Tracking issue: #226
+- Scope:
+  - Én shared key-map for lobby/kerneflow
+  - Locale-kontrakt (tilladte locales, default locale, fallback-regler)
+  - Dokumentation af naming + ownership
+- Mergebarhed: Kan merges uden host/player UI-migrering.
+- Acceptance:
+  - Shared kontrakt findes ét sted
+  - Begge sider kan importere den
+  - Docs opdateret med da/en eksempler
+
+### C) Angular host/player integration + hardcoded-text cleanup
+- Tracking issue: #227
+- Scope:
+  - Angular host/player kerneflow bruger shared keys
+  - Hardcoded tekster fjernes i aftalte kernekomponenter
+  - Sprogskift verificeres i kritiske states
+- Mergebarhed: Kan merges selvstændigt når frontend-tests er grønne.
+- Acceptance:
+  - Korrekt i18n-copy i da/en i kerneflow
+  - Ingen hardcoded kerneflow-tekster tilbage
+  - Frontend tests/smoke grønne
+
+## PR-grænser (per bid)
+- 1 PR pr. bid (A/B/C) mod `main`
+- Mål: ~200–300 net LOC per PR (ekskl. generated artefakter)
+- Undgå cross-layer scope creep
+- Review-tid <30 min
+
+## Overordnet acceptance for #224
+- A/B/C-sekvens er tydelig med links
+- Hver bid er mergebar isoleret
+- Scheduler kan assign’e direkte uden ekstra afklaring
+
+## Verification (docs-only)
+- Verificeret at dokumentet kun beskriver trunk-sekvensen for issue #224 og linker til #225/#226/#227.
+- Ingen runtime-kode ændret; der er derfor ikke kørt kode/tests i denne PR.

docs/ISSUE-225-BACKEND-I18N-BASELINE-ARTIFACT.md

@@ -0,0 +1,44 @@
+# ISSUE-225 Artifact — Backend i18n baseline (resolver + fallback)
+
+Issue: **#225** (`[MVP][READY] #175-A: Backend i18n baseline (resolver + fallback)`)
+
+## Scope verified
+
+- Backend locale resolver supports `da` + `en` and normalizes language tags.
+- Unsupported locale requests fall back to default locale (`en`).
+- Error payload contract is stable for API errors:
+  - `error_code`
+  - `error`
+  - `locale`
+
+## Implementation references
+
+- Locale resolution + fallback chain:
+  - `lobby/i18n.py`
+  - `resolve_locale()`
+  - `resolve_error_message()`
+  - `api_error()`
+- Shared locale contract source:
+  - `shared/i18n/lobby.json` (`locales.default=en`, supported includes `en`, `da`)
+
+## Acceptance checks run
+
+Command:
+
+```bash
+.venv/bin/python manage.py test \
+  lobby.tests.I18nResolverTests \
+  lobby.tests.LobbyFlowTests \
+  lobby.tests.StartRoundTests
+```
+
+Result (2026-03-02):
+
+- `Ran 28 tests in 24.781s — OK`
+- `System check identified no issues (0 silenced).`
+- Confirms resolver behavior for locale normalization + fallback and stable error payload fields across flow endpoints.
+
+## Notes
+
+- Existing merged follow-ups in `main` include Accept-Language parsing fixes for q-values and locale tag normalization.
+- This artifact documents the final baseline state and verification evidence for #225.

docs/ISSUE-226-SHARED-KEYMAP-LOCALE-CONTRACT.md

@@ -0,0 +1,30 @@
+# ISSUE-226 — Shared key-map + locale-kontrakt (backend/frontend)
+
+## Source of truth
+- Single shared artifact: `shared/i18n/lobby.json`
+- Ownership is documented under `contract.ownership` in the same artifact.
+
+## Locale contract
+Defined under `contract.locale`:
+- default locale: `en`
+- supported locales: `en`, `da`
+- fallback rule: use default locale when requested locale is unsupported or a key translation is missing.
+
+## Shared backend→frontend key-map
+Defined under `contract.backend_to_frontend_error_keys`.
+
+Examples:
+- `session_not_found -> session_not_found`
+- `session_not_joinable -> join_failed`
+- `round_start_invalid_phase -> start_round_failed`
+
+This allows backend error codes to remain stable while frontend copy keys stay UX-oriented.
+
+## da/en example values
+From `shared/i18n/lobby.json`:
+- `frontend.errors.session_code_required.en = "Session code is required."`
+- `frontend.errors.session_code_required.da = "Sessionskoden er påkrævet."`
+
+## Verification
+- Backend: `python manage.py test lobby.tests.I18nResolverTests`
+- Frontend: `npm test -- --run tests/lobby-i18n.contract.test.ts`

docs/ISSUE-250-PRIMARY-DEVICE-AUDIO-POLICY-ARTIFACT.md

@@ -0,0 +1,16 @@
+# Issue #250 Artifact — MVP guardrail (telefon-klient uden lydafspilning)
+
+## Scope
+Implementeret guardrail for `primary-device only` audio policy i SPA player-flow.
+
+## Acceptance mapping
+1. **Telefon-klient flow indeholder ingen audio-play init-path**
+   - Test: `player-shell.component.spec.ts` → `does not trigger original media play during player-shell init path`.
+2. **Primær enhed policy er dokumenteret og testbar**
+   - Policy i contract: `shared/i18n/lobby.json` → `frontend.capabilities.client_has_no_audio_output=true`.
+   - Testbar via eksisterende guard-tests + init-path test i player-shell specs.
+3. **Krav er refereret i SPA-plan/cutover-noter**
+   - Dokumenteret i `docs/spa-cutover-flag.md` under *MVP audio policy guardrail (telefon-klient)*.
+
+## UX/i18n note
+- Player shell viser advarselstekst via i18n key: `frontend.ui.player.audio_policy_notice`.

docs/ISSUE-251-RELEASE-OFTEN-SPA-MVP-BATCH-PLAN.md

@@ -0,0 +1,124 @@
+# Issue #251 — Release-often lane for SPA MVP (3 micro-PR batches)
+
+## Formål
+Bryde SPA MVP-arbejdet op i **3 merge-klare micro-PRs** med tydelige acceptance criteria,
+så vi kan levere værdi oftere, reducere review-risiko og holde `main` grøn.
+
+## Scope (issue-bound)
+Denne plan dækker kun planlægning/acceptance for den kommende SPA MVP-lane.
+Implementering af de konkrete features sker i efterfølgende PRs.
+
+## Hard acceptance criteria for issue #251
+- [x] Der findes en dokumenteret plan med præcis **3 batches**.
+- [x] Hver batch har:
+  - [x] mål og afgrænsning
+  - [x] konkrete leverancer (kodeområder)
+  - [x] test/checks før merge
+  - [x] rollback-note
+  - [x] "ikke med i denne batch" for at undgå scope creep
+- [x] Batch-rækkefølgen er dependencies-sikker (batch B bygger på batch A, batch C på batch B).
+- [x] Hver batch kan merges/releaseres uafhængigt uden at blokere drift på `main`.
+- [x] Planen linker til konkrete dev-opgaver for lane-kørsel.
+
+## Batch-plan (merge-klare micro-PRs)
+
+### Batch A — SPA shell + routing baseline
+**Mål:** Et stabilt SPA-skelet med route-struktur og guard-basics.
+
+**Leverancer (kodeområder)**
+- `frontend/angular/src/app/app.routes.ts` (host/player entry routes + fallback)
+- `frontend/angular/src/app/session-route-context.ts` (baseline route guards)
+- `frontend/angular/src/app/app.component.*` (shell-nav + route outlet wiring)
+- `lobby/templates/lobby/spa_shell.html` (kompatibel shell-entry ved SPA cutover)
+
+**Done-kriterier**
+- Host- og player-entry routes kan åbnes uden runtime-fejl i samme SPA-shell.
+- Route guards afviser ugyldige parametre deterministisk (ingen hard crash).
+- `USE_SPA_UI=false` fortsætter med legacy-flow uden regression.
+
+**Checks før merge**
+- `cd frontend/angular && npm test -- --run src/app/app.routes.spec.ts src/app/session-route-context.spec.ts`
+- `cd frontend/angular && npm run build`
+- Manual smoke: `/lobby/ui/host` + `/lobby/ui/player` (både `USE_SPA_UI=false` og `true`).
+
+**Rollback-note**
+- Sæt `USE_SPA_UI=false` og redeploy; verificér legacy routes svarer 200.
+
+**Ikke med i batch A**
+- Fuld gameplay-state synkronisering.
+- Audio/polish og i18n finpudsning ud over baseline wiring.
+
+---
+
+### Batch B — Session-state + host/player sync MVP
+**Mål:** Korrekt synkronisering af session-state mellem host og spillerklient.
+
+**Leverancer (kodeområder)**
+- `frontend/angular/src/app/features/host/host-shell.component.ts`
+- `frontend/angular/src/app/features/player/player-shell.component.ts`
+- `frontend/src/api/angular-client.ts` (MVP-kald for status/phase-overgange)
+
+**Done-kriterier**
+- Host handlinger (`start`, `show`, `mix`, `score`, `next`, `finish`) afspejles hos player uden side-reload.
+- Session-phase transitions er deterministiske i happy-path (`lobby -> question -> score -> next/finish`).
+- Guardrails reducerer race-condition regressions ved hurtige phase-skift.
+
+**Checks før merge**
+- `cd frontend/angular && npm test -- --run src/app/features/host/host-shell.component.spec.ts src/app/features/player/player-shell.component.spec.ts`
+- `cd frontend && npm test -- --run tests/angular-api-client.test.ts`
+- Manual smoke: host action -> player phase sync indenfor forventet latenstid.
+
+**Rollback-note**
+- Slå `USE_SPA_UI=false`, redeploy, og kør hurtig gameplay-smoke i legacy flow.
+
+**Ikke med i batch B**
+- Avanceret UX-polish/animation.
+- Udvidet observability udenfor MVP-kritiske logs.
+
+---
+
+### Batch C — Lobby/join/start minimal flow + release readiness
+**Mål:** Gøre SPA MVP release-klar med fokus på stabilitet og driftssikkerhed omkring det minimale flow.
+
+**Leverancer (kodeområder)**
+- `frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts` + relevante shell-tests
+- `docs/UI_SMOKE.md` + `docs/STAGING_GAMEPLAY_SMOKE_ARTIFACT.md`
+- `CHANGELOG.md` release-input for SPA MVP lane
+
+**Done-kriterier**
+- End-to-end minimal flow (`lobby -> join -> start`) er dokumenteret PASS i SPA.
+- Fejl-/empty-/loading states for flowets kritiske skærme er verificeret.
+- Driftsteam kan udføre cutover + rollback uden tvetydighed.
+
+**Checks før merge**
+- `cd frontend/angular && npm test -- --run src/app/i18n-mvp-flow-smoke.spec.ts`
+- `python manage.py test lobby.tests.LobbyFlowTests`
+- Opdateret staging-smoke artifact med UTC tidsstempler og gate-resultat.
+
+**Rollback-note**
+- Brug eksisterende playbook i `docs/spa-cutover-flag.md` (`USE_SPA_UI=false` + asset-version rollback).
+
+**Ikke med i batch C**
+- Post-MVP featureudvidelser.
+- Større refactors uden direkte release-værdi.
+
+## Rækkefølge og parallel-kørsel
+- **Dependency-rækkefølge:** A -> B -> C.
+- **Kan køres parallelt uden konflikt:**
+  - Test-/doc-forberedelse til C kan startes parallelt med B (ingen blokering af runtime-kode), men merges først efter B.
+  - Drift-smoke templates kan opdateres tidligt, så længe de ikke ændrer runtime-adfærd.
+- **Må ikke køre parallelt:**
+  - Runtime routing/guard ændringer i A og session-sync logik i B på samme filer uden feature-flag koordinering.
+
+## Konkret lane-opgavebinding (dev-opgaver)
+- Batch A PR: `feat/issue-251-batch-1-spa-shell-routing`
+- Batch B PR: `feat/issue-251-batch-2-session-sync`
+- Batch C PR: `feat/issue-251-batch-3-lobby-join-start-release-readiness`
+
+Hver PR skal linke tilbage til issue #251 og inkludere test-evidence + rollback-check.
+
+## Merge-gate for alle 3 batches
+- Små PRs (mål: reviewbar størrelse, helst < ~300 netto-linjer når muligt).
+- Grøn CI/checks før review-request.
+- Tydelig PR-beskrivelse med: scope, test evidence, out-of-scope.
+- Ingen skjulte sideeffekter på tværs af apps/domæner.

docs/ISSUE-252-REACT-FALLBACK-TRIGGERS-ARTIFACT.md

@@ -0,0 +1,27 @@
+# ISSUE-252 Artifact — React fallback trigger criteria (delivery-blocking only)
+
+Issue: **#252**
+
+## Leveret ændring
+Dokumentationen i `docs/spa-cutover-flag.md` er opdateret med en dedikeret sektion:
+- **React fallback trigger-kriterier (kun delivery-blocking)**
+- klare **tilladelses-kriterier** (alle skal være opfyldt)
+- tydelige **scope-limits**
+- eksplicitte **ikke-tilladte** anvendelser
+
+## Acceptance mapping
+1. **Clear trigger criteria**
+   - Definerer præcist hvornår fallback er tilladt:
+     - aktiv delivery-blocking fejl i Angular SPA
+     - ingen sikker Angular-fix inden release-vinduet
+     - rollback alene er utilstrækkelig for leveringsbehovet
+     - beslutning + evidens logges eksplicit (inkl. issue/incident-reference)
+2. **Scope limits**
+   - Begrænset til delivery-blocking host/player-paths.
+   - Ingen feature-bundling eller ikke-kritiske ændringer.
+   - Midlertidig anvendelse kun i aktiv incident/release-vindue.
+3. **When fallback is allowed**
+   - Kun når alle trigger-kriterier er opfyldt og dokumenteret.
+
+## Resultat
+Issue #252 er dokumenteret med operationelle guardrails, så React fallback kun bruges i kontrollerede, leveringsblokerende situationer.

docs/ISSUE-257-SHARED-I18N-KEYSPACE-FRONTEND-LOADER-ARTIFACT.md

@@ -0,0 +1,32 @@
+# ISSUE-257 Artifact — Shared i18n keyspace + frontend loader (da/en, Angular-first)
+
+Issue: **#257** (`[MVP][READY] #175-B: Shared i18n keyspace + frontend loader`)
+
+## Acceptance checklist
+
+- [x] **Delt key-strategi dokumenteret (frontend/backend)**
+  - Arkitektur/deling beskrevet i `docs/I18N_ARCHITECTURE.md`.
+  - Shared contract + keyspace source of truth: `shared/i18n/lobby.json`.
+
+- [x] **Frontend loader kan indlæse da+en med samme keyspace**
+  - Shared loader: `frontend/shared/i18n/lobby-loader.ts`.
+  - Angular-first integration via `frontend/angular/src/app/lobby-i18n.ts` (samme loader/samme keyspace).
+  - Locale-normalisering inkluderer underscore/hyphen variants (`da_DK` → `da`).
+
+- [x] **Minimal check for key-paritet da/en**
+  - `collectLocaleParityIssues(...)` i shared loader.
+  - Testet i `frontend/tests/lobby-loader.parity.test.ts`.
+
+- [x] **Ingen API-kontraktbrud**
+  - Contract-test: `frontend/tests/lobby-i18n.contract.test.ts`.
+  - Drift-check mellem manifest og katalog: `scripts/check_i18n_drift.py`.
+
+## Kørte checks
+
+```bash
+python3 scripts/check_i18n_drift.py
+cd frontend && npm test -- --run tests/lobby-loader.parity.test.ts tests/lobby-i18n.contract.test.ts
+cd frontend/angular && npm test -- --run src/app/lobby-i18n.spec.ts src/app/i18n-mvp-flow-smoke.spec.ts
+```
+
+Resultat: alle checks grønne.

docs/ISSUE-257-SHARED-I18N-LOADER-ARTIFACT.md

@@ -0,0 +1,37 @@
+# ISSUE-257 Artifact — shared i18n keyspace + frontend loader (Angular-first)
+
+Issue: **#257** (`[MVP][READY] #175-B: Shared i18n keyspace + frontend loader (da/en, Angular-first)`)
+
+## Acceptance mapping
+
+### 1) Delt key-strategi dokumenteret (frontend/backend)
+- Shared contract source: `shared/i18n/lobby.json`
+- Architecture doc: `docs/I18N_ARCHITECTURE.md`
+- Key-map/contract doc: `docs/ISSUE-226-SHARED-KEYMAP-LOCALE-CONTRACT.md`
+
+### 2) Frontend loader kan indlæse da+en med samme keyspace
+- Shared loader: `frontend/shared/i18n/lobby-loader.ts`
+- Angular-first consumer path:
+  - `frontend/src/spa/lobby-i18n.ts`
+  - Angular shell/tests continue to consume same shared catalog through shared loader contract.
+
+### 3) Minimal check for key-paritet da/en
+- Guard test: `frontend/tests/lobby-loader.parity.test.ts`
+- Contract test: `frontend/tests/lobby-i18n.contract.test.ts`
+
+### 4) Ingen API-kontraktbrud
+- Frontend API contract smoke:
+  - `frontend/angular/src/app/api-contract-smoke.spec.ts`
+  - `frontend/tests/angular-api-client.test.ts`
+
+## Verification run (this lane)
+
+```bash
+cd frontend
+npm test -- --run tests/lobby-loader.parity.test.ts tests/lobby-i18n.contract.test.ts tests/angular-api-client.test.ts
+
+cd ../frontend/angular
+npm test -- --run src/app/api-contract-smoke.spec.ts
+```
+
+Result: PASS (all selected suites green).

docs/ISSUE-260-PHONE-CLIENT-NO-AUDIO-GUARD-ARTIFACT.md

@@ -0,0 +1,18 @@
+# Issue #260 Artifact — Phone/client no-audio guard (primary-device only playback)
+
+## Scope
+Added regression coverage for MVP audio policy to ensure phone/client flows never claim playback ownership, while primary-device playback stays unaffected.
+
+## Acceptance mapping
+1. **client/phone triggers no playback**
+   - Existing test coverage retained in `player-shell.component.spec.ts`:
+     - `does not trigger original media play during player-shell init path`
+     - `installs secondary-device audio guard while player shell is mounted`
+2. **primary device playback unaffected**
+   - New negative test in `player-shell.component.spec.ts`:
+     - `keeps primary-device playback untouched when no-audio capability is disabled`
+3. **one negative test for phone audio**
+   - Existing negative path preserved:
+     - `does not trigger original media play during player-shell init path`
+4. **no backend contract changes**
+   - Frontend test/docs-only scope; no backend contract files changed.

docs/ISSUE-277-SHARED-I18N-PARITY-ARTIFACT.md

@@ -0,0 +1,80 @@
+# ISSUE-277 Artifact — shared i18n registry parity report (Django ↔ Angular MVP)
+
+Issue: **#277** (`[READY][#175][P3] Shared i18n registry artifact: backend/frontend keyspace parity report`)
+
+## Artifact metadata
+
+- `artifact_id`: `issue-277-shared-i18n-parity-report`
+- `artifact_version`: `1.0`
+- `catalog_source`: `shared/i18n/lobby.json`
+- `generator`: `scripts/report_i18n_parity.py`
+
+## Naming/version rules (email-manager-inspired strategy)
+
+- **Single canonical artifact per issue**: issue-bundne rapporter navngives `docs/ISSUE-<nr>-<slug>-ARTIFACT.md`.
+- **Stable artifact identity**: `artifact_id` ændres ikke ved tekstlige opdateringer i samme rapporttype; det er den faste reference i review/ops.
+- **Explicit artifact versioning**: `artifact_version` bumpes, når rapportlogik eller scope ændres, så drift/review kan se forskel på format- vs. dataændringer.
+- **Shared namespace first**: keys refereres med fulde navnerum (`frontend.ui.*`, `frontend.errors.*`, `backend.error_codes.*`, `backend.errors.*`) i stedet for lokale aliases i artefakter.
+- **Source-of-truth before consumers**: rapporten afledes fra `shared/i18n/lobby.json`; Django/Angular beskrives som consumers af samme registry og ikke som parallelle kontrakter.
+
+## MVP-critical parity summary
+
+- Frontend UI gameplay keys checked: **16** → `OK`
+- Frontend error keys checked: **7** → `OK`
+- Backend gameplay/error codes checked: **9** → `OK`
+- Distinct frontend error keys reached from backend MVP flow: **6** (`join_failed, nickname_invalid, nickname_taken, session_code_required, session_not_found, start_round_failed`)
+
+Status: **Shared locale matrix is aligned (`en`, `da`) and backend→frontend error handling is contract-complete for MVP-critical flow.**
+
+## Django ↔ Angular parity matrix (MVP-critical error contract)
+
+| Backend code (`backend.error_codes.*`) | Django message key (`backend.errors.*`) | Angular key (`frontend.errors.*`) | Locales `en/da` | Parity note |
+|---|---|---|---|---|
+| `session_code_required` | `session_code_required` | `session_code_required` | `OK` | 1:1 |
+| `nickname_invalid` | `nickname_invalid` | `nickname_invalid` | `OK` | 1:1 |
+| `session_not_found` | `session_not_found` | `session_not_found` | `OK` | 1:1 |
+| `session_not_joinable` | `session_not_joinable` | `join_failed` | `OK` | mapped alias |
+| `nickname_taken` | `nickname_taken` | `nickname_taken` | `OK` | 1:1 |
+| `category_slug_required` | `category_slug_required` | `start_round_failed` | `OK` | many:1 collapse |
+| `category_not_found` | `category_not_found` | `start_round_failed` | `OK` | many:1 collapse |
+| `round_start_invalid_phase` | `round_start_invalid_phase` | `start_round_failed` | `OK` | many:1 collapse |
+| `round_already_configured` | `round_already_configured` | `start_round_failed` | `OK` | many:1 collapse |
+
+## Scope notes
+
+- **Django** consumes backend codes/messages directly from `shared/i18n/lobby.json` via `lobby/i18n.py`.
+- **Angular** consumes the same registry via `frontend/shared/i18n/lobby-loader.ts` and runtime helpers in `frontend/angular/src/app/lobby-i18n.ts`.
+- **Parity in MVP** is therefore strongest on the shared error contract and locale matrix; gameplay UI labels are frontend-owned but still live in the same registry.
+
+## Verified MVP gameplay UI keyspace present in the shared registry
+
+- `frontend.ui.host.title`
+- `frontend.ui.player.title`
+- `frontend.ui.common.session_code`
+- `frontend.ui.player.nickname`
+- `frontend.ui.player.join`
+- `frontend.ui.host.start_round`
+- `frontend.ui.host.show_question`
+- `frontend.ui.player.lie_label`
+- `frontend.ui.player.submit_lie`
+- `frontend.ui.player.submit_guess`
+- `frontend.ui.host.mix_answers`
+- `frontend.ui.host.calculate_scores`
+- `frontend.ui.host.load_scoreboard`
+- `frontend.ui.host.final_leaderboard`
+- `frontend.ui.player.final_leaderboard`
+- `frontend.ui.common.points_short`
+
+## Concrete deviations / follow-up items
+
+1. **Error granularity collapse remains intentional**: backend codes `category_slug_required, category_not_found, round_start_invalid_phase, round_already_configured` all map to `frontend.errors.start_round_failed`. Follow-up only if product wants case-specific Angular copy instead of one shared host failure message.
+2. **Frontend-only fallback copy is not mirrored in Django**: `frontend.errors.unknown` and `frontend.errors.session_fetch_failed` are Angular-side resilience keys, not backend contract keys. Follow-up if API responses should expose stable backend equivalents for these states.
+3. **Gameplay UI labels are registry-shared but not backend-rendered**: `frontend.ui.host.*`, `frontend.ui.player.*`, and `frontend.ui.common.*` are available in the shared artifact, but Django currently consumes only the backend error slice. Follow-up only if server-rendered views must guarantee the same UI label surface as Angular.
+
+## Re-run
+
+```bash
+python3 scripts/check_i18n_drift.py
+python3 scripts/report_i18n_parity.py
+python3 scripts/check_i18n_parity_artifact.py
+```

docs/ISSUE-278-SMOKE-E2E-GATE-ARTIFACT.md

@@ -0,0 +1,36 @@
+# Issue #278 Artifact — smoke/e2e gate for da+en locale flow and primary-only audio
+
+## Scope
+Acceptance for `[READY][#175][P4]`:
+1. Verify one MVP host+player smoke run in `en`.
+2. Verify one MVP host+player smoke run in `da`.
+3. Verify audio routing remains `primary-device only` so phone/player clients never take playback ownership.
+
+Dette er en gate-/evidensleverance. Ingen ny produktfunktion ud over test/verifikation.
+
+## Implemented smoke gate
+Angular smoke spec: `frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts`
+
+The gate now runs two explicit locale scenarios:
+- `en`: host refresh/start-round copy + player submit-guess copy
+- `da`: samme flow med dansk copy
+
+Audio-policy delen af samme smoke-spec verificerer:
+- host/primary playback path er uændret før player mount
+- player mount installerer no-audio guard på secondary device
+- guard fjernes igen ved unmount, så primary path fortsat er eneste aktive output
+
+## Recommended verification command
+Køres fra `frontend/angular`:
+
+```bash
+npm test -- --run src/app/i18n-mvp-flow-smoke.spec.ts src/app/lobby-i18n.spec.ts src/app/features/player/player-shell.component.spec.ts
+```
+
+## Why this is the gate
+- `i18n-mvp-flow-smoke.spec.ts` giver en lille, samlet smoke/e2e-lignende verifikation af host+player i begge locale-kontekster.
+- `lobby-i18n.spec.ts` holder shared locale propagation + contract fallback grøn.
+- `player-shell.component.spec.ts` dækker den dybere regressionflade for audio-guard på secondary device.
+
+## Conclusion
+Gate’en verificerer nu eksplicit begge locale-runs (`da` + `en`) og bekræfter primary-only audio routing i MVP-flowet.

docs/ISSUE-279-I18N-MVP-CLOSEOUT.md

@@ -0,0 +1,168 @@
+# ISSUE-279 — i18n MVP close-out note
+
+Issue: **#279** (`[READY][#175][P5] MVP close-out note: migration/changelog + release-readiness checklist for i18n`)
+
+## Scope
+
+Dette dokument lukker MVP-sporet for issue #175 med tre konkrete ting:
+
+1. en migrationsnote for release/deploy,
+2. changelog-indhold der kan genbruges i næste release-note,
+3. en release-readiness checkliste for i18n, forankret i et verificeret snapshot af `main` ved reviewtidspunktet.
+
+Repo-state ved review-opdatering:
+- `main` peger nu på merge commit `1bc4c27` (PR #283), og inkluderer også PR #282 via merge commit `6ad5430`.
+- Denne note er opdateret mod repo-tilstanden verificeret 2026-03-13 UTC, ikke en løbende garanti for senere `main`-ændringer.
+- Denne revision afløser de tidligere snapshot-antagelser fra PR-historikken, hvor #282/#283 endnu ikke var landet.
+- Der er ingen åbne release-afklaringer tilbage for PR #282/#283; begge er allerede landet på `main`.
+
+## Current i18n MVP state on `main`
+
+Følgende er allerede til stede på `main`:
+
+- **Shared contract** i `shared/i18n/lobby.json`
+  - default locale: `en`
+  - supported locales: `en`, `da`
+  - fælles frontend/backend keyspace + fallback-regler
+- **Django bootstrap** via `partyhub/i18n_bootstrap.py` og `partyhub/settings.py`
+  - `LocaleMiddleware` aktiv
+  - `LANGUAGE_CODE` + `LANGUAGES` bootstrappes fra shared catalog
+- **Backend locale/error flow** via `lobby/i18n.py`
+  - normalisering af locale-tags
+  - locale-aware fejlpayload med `error_code`, `error`, `locale`
+  - fallback til `en` når locale eller oversættelse mangler
+- **Angular MVP wiring** via
+  - `frontend/shared/i18n/lobby-loader.ts`
+  - `frontend/angular/src/app/lobby-i18n.ts`
+  - host/player shells med locale switch og shared copy-opslag
+- **Drift/parity guardrails**
+  - `shared/i18n/key-manifest.json`
+  - `scripts/check_i18n_drift.py`
+  - frontend parity/contract tests
+- **Existing documentation/artifacts**
+  - `docs/I18N_ARCHITECTURE.md`
+  - `docs/ISSUE-175-I18N-SHARED-CONTRACT-ARTIFACT.md`
+  - `docs/ISSUE-225-BACKEND-I18N-BASELINE-ARTIFACT.md`
+  - `docs/ISSUE-257-SHARED-I18N-KEYSPACE-FRONTEND-LOADER-ARTIFACT.md`
+  - `docs/ISSUE-207-I18N-AUDIO-SMOKE-ARTIFACT.md`
+  - `docs/i18n-drift-check.md`
+
+## Migration note for release
+
+### Schema impact
+
+**Der er ingen nye Django-migrations i selve i18n-MVP-sporet på `main`.**
+
+Den i18n-relaterede leverance ligger i shared catalog, locale-bootstrap, error-payload-kontrakt, Angular wiring og test/documentation. Den kræver derfor ikke en særskilt i18n-database-migration for at gå i release.
+
+### Release/deploy expectation
+
+Selv om issue #279 ikke introducerer schemaændringer, skal release-flow stadig følge repoets generelle migreringsgate:
+
+```bash
+python manage.py makemigrations --check --dry-run
+python manage.py migrate --check --noinput
+```
+
+Hvorfor: release-policyen kræver, at vi undgår code/schema drift, og staging-smoke-suiten forventer eksplicit migration consistency check.
+
+### Praktisk migrationskonklusion
+
+Til release-notes/deploy-runbook kan i18n-sporet beskrives sådan her:
+
+- **Migration impact:** none for i18n MVP itself
+- **Deploy requirement:** run standard Django migration consistency checks anyway
+- **Rollback note:** rollback er primært kode-/asset-baseret (shared catalog, frontend bundles, backend locale resolver), ikke schema-baseret
+
+## Suggested changelog content
+
+Følgende tekst kan bruges direkte i næste unreleased/release-sektion:
+
+```markdown
+### i18n
+- Shared da/en lobby i18n contract is now wired across Django and Angular MVP flows via `shared/i18n/lobby.json`.
+- Backend error payloads expose stable locale-aware fields (`error_code`, `error`, `locale`) with fallback to English for unsupported locales.
+- Angular host/player shells now consume shared i18n copy, persist preferred locale, and keep audio-policy messaging aligned with the shared catalog.
+- Added repo guardrails for i18n drift/parity through the shared key manifest, drift checker, and focused frontend/backend contract tests.
+- Release migration impact for the i18n MVP is **none** beyond the standard Django migration consistency checks.
+```
+
+Kort version til annoterede release-notes:
+
+```markdown
+## i18n MVP close-out
+- Shared da/en contract is active across backend + Angular MVP shell.
+- Locale fallback remains `en` for unsupported requests and missing translations.
+- No i18n-specific schema migration is required; keep standard `migrate --check --noinput` in release verification.
+```
+
+## Release-readiness checklist for i18n
+
+Status er vurderet mod verificeret snapshot `main@1bc4c27` (reviewet 2026-03-13 UTC, inkl. PR #282/#283).
+
+### 1) Shared contract and locale behavior
+
+- [x] Shared catalog findes i `shared/i18n/lobby.json`.
+- [x] Default/supported locales er dokumenteret og implementeret som `en` + `da`.
+- [x] Backend bruger shared contract til locale-aware fejlbeskeder.
+- [x] Frontend/Angular bruger shared loader + shared keyspace.
+- [x] Fallback-regel til `en` er dokumenteret og testet.
+
+### 2) Verification artifacts and local checks
+
+- [x] Arkitektur-note findes: `docs/I18N_ARCHITECTURE.md`.
+- [x] Baseline artifact for issue #175 findes.
+- [x] Backend artifact for issue #225 findes.
+- [x] Frontend/shared loader artifact for issue #257 findes.
+- [x] Drift-check dokumentation findes i `docs/i18n-drift-check.md`.
+- [x] Parity artifact fra issue #277 er på `main` via PR #282 (merge commit `6ad5430`).
+
+### 3) Code readiness on current branch topology
+
+- [x] Angular MVP host/player i18n flow er på `main` (PR #281).
+- [x] Shared locale/bootstrap wiring er på `main`.
+- [x] Django i18n hardening fra issue #275 er på `main` via PR #283 (merge commit `1bc4c27`).
+- [x] PR #283 er ikke længere en separat release-afklaring; hardeningen er allerede indarbejdet på `main`.
+
+### 4) Release gate before shipping i18n as “done”
+
+- [x] PR #282 er allerede merged, så parity-artifact-status er afklaret på `main`.
+- [x] PR #283 er allerede merged, så backend hardening-status er afklaret på `main`.
+- [ ] Kør drift-check fra repo root:
+  ```bash
+  python3 scripts/check_i18n_drift.py
+  ```
+- [ ] Kør backend i18n regressions:
+  ```bash
+  . .venv/bin/activate && python manage.py test \
+    partyhub.tests_i18n_bootstrap \
+    lobby.tests.I18nResolverTests
+  ```
+- [ ] Kør frontend shared-contract/parity checks:
+  ```bash
+  cd frontend && npm test -- --run \
+    tests/lobby-loader.parity.test.ts \
+    tests/lobby-i18n.contract.test.ts
+  ```
+- [ ] Kør Angular MVP locale smoke:
+  ```bash
+  cd frontend/angular && npm test -- --run \
+    src/app/lobby-i18n.spec.ts \
+    src/app/i18n-mvp-flow-smoke.spec.ts \
+    src/app/features/host/host-shell.component.spec.ts \
+    src/app/features/player/player-shell.component.spec.ts
+  ```
+- [ ] Bekræft standard migration consistency gate:
+  ```bash
+  . .venv/bin/activate && python manage.py makemigrations --check --dry-run
+  . .venv/bin/activate && python manage.py migrate --check --noinput
+  ```
+- [ ] Følg `docs/RELEASE_POLICY.md`: staging deploy, `/healthz`, smoke-resultat og changelog-reference før tag.
+
+## Close-out conclusion
+
+**Konklusion:** i18n-MVP'en er implementeret på `main`, og issue #279 leverer den manglende release-/migration-closeout dokumentation uden nye kodeændringer i app-logikken.
+
+PR #282 (parity artifact) og PR #283 (Django i18n hardening) er nu begge merged på `main`, så close-out-noten, changelog-teksten og release-readiness-checklisten kan behandles som indbyrdes konsistente for det verificerede snapshot.
+
+Det betyder, at de resterende release-gates for i18n nu er de almindelige verificeringstrin (drift-check, backend/frontend-smoke, migrations-konsistens, staging deploy og changelog-reference) — ikke længere afklaring af om #282/#283 skal lande.

docs/ISSUE-287-CANONICAL-ROUND-FLOW-BACKEND-ARTIFACT.md

@@ -0,0 +1,22 @@
+# Issue #287 — Canonical round-flow backend artifact
+
+## State-transition matrix
+
+| Trigger | From | To | Server-owned effect |
+|---|---|---|---|
+| `POST /lobby/sessions/{code}/rounds/start` | `lobby` | `lie` | Opretter `RoundConfig`, vælger/låser konkret `RoundQuestion`, eksponerer prompt + lie-deadline i samme svar |
+| Sidste gyldige `submit_lie` for aktivt spørgsmål | `lie` | `guess` | Dedupe/shuffle `correct_answer + lies`, persisterer `mixed_answers`, broadcaster `phase.guess_started` |
+| Sidste gyldige `submit_guess` for aktivt spørgsmål | `guess` | `reveal` | Beregner score deterministisk, persisterer `ScoreEvent` + opdaterede `Player.score`, returnerer canonical reveal payload |
+| Første canonical state-read efter resolved reveal (`session_detail`, og idempotent `GET /scoreboard` hvis state allerede er resolved) | `reveal` | `scoreboard` | Promoverer scoreboard som state, broadcaster `phase.scoreboard`, eksponerer leaderboard + readiness |
+| `POST /lobby/sessions/{code}/rounds/next` | `scoreboard` | `lie` | Increment round counter, kopierer seneste `RoundConfig`, vælger/låser næste spørgsmål i samme kategori og broadcaster `phase.lie_started` |
+| `POST /lobby/sessions/{code}/finish` | `scoreboard` | `finished` | Fryser slutresultat og returnerer final leaderboard |
+
+## Flow-log (happy path)
+
+1. Host starter runde med kategori.
+2. Server vælger straks spørgsmål og går i `lie`.
+3. Spillere sender løgne; sidste submission auto-advancer til `guess`.
+4. Spillere sender gæt; sidste submission auto-advancer til `reveal` og scorer runden.
+5. Næste canonical state-read promoverer resolved reveal til `scoreboard`; state findes uden separat debug-knap.
+6. Host kan nu kun vælge `next round` eller `finish game`.
+7. `next round` starter næste runde direkte i `lie` med nyt konkret spørgsmål; ingen mellem-hop tilbage til `lobby`.

docs/ISSUE-301-CLIENT-ACTION-GATING-ARTIFACT.md

@@ -0,0 +1,52 @@
+# Issue #301 Artifact — Client action gating from canonical phase state
+
+Refs: #287, #301
+
+## What changed
+
+Frontend host/player shells now prefer the canonical phase exposed by `phase_view_model.current_phase` when deciding:
+
+- which gameplay actions are enabled
+- whether reveal data should still be shown
+- which SPA hash-route should represent the active game state
+
+This tightens the #301 slice so the client stays aligned with backend canonicalisation even when `session.status` lags during reveal/scoreboard promotion.
+
+## Gated UI actions by phase
+
+### Lobby
+- **Host:** `startRound`
+- **Player:** `join`
+
+### Bluff / lie
+- **Host:** `showQuestion`
+- **Player:** `submitLie`
+- **Blocked:** guess submission, scoreboard load, next round, finish game
+
+### Guess
+- **Host:** `mixAnswers`, `calculateScores`
+- **Player:** `submitGuess`
+- **Blocked:** lie submission, scoreboard load, next round, finish game
+
+### Reveal
+- **Host:** `loadScoreboard`
+- **Player:** display-only reveal state
+- **Blocked:** start next round, finish game, guess/lie submission
+
+### Scoreboard
+- **Host:** `startNextRound`, `finishGame`
+- **Player:** display-only reveal/scoreboard state
+- **Blocked:** scoreboard reload, guess/lie submission
+
+## Test evidence
+
+Targeted tests added/updated for:
+
+- host shell canonical gating and route sync when `current_phase` differs from `session.status`
+- player shell canonical gating and route sync when `current_phase` differs from `session.status`
+- shared gameplay phase machine gating from canonical permissions
+- shared API mapper contract coverage, including reveal/scoreboard payload stability
+
+## Contract note
+
+No backend protocol redesign was introduced. This follow-up only preserves and consumes the existing canonical phase/action contract more strictly on the client side.

docs/ISSUE-302-CANONICAL-LOOP-EVIDENCE.md

@@ -0,0 +1,55 @@
+# Issue #302 Evidence — canonical bluff → guess → reveal → scoreboard regression
+
+## Runnable command
+
+```bash
+python manage.py migrate --noinput
+python manage.py smoke_staging --artifact docs/artifacts/issue-302-canonical-loop-smoke.json
+```
+
+`migrate` is the normal local bootstrap precondition when the database has not been initialized yet; the regression evidence itself is produced by `smoke_staging`.
+
+## What the regression proves
+
+`smoke_staging` now exercises one full canonical round and fails fast with step-specific diagnostics if any of these break:
+
+1. `start_round` lands the session in `lie` and returns a concrete `round_question_id`.
+2. Final `submit_lie` auto-advances the session to `guess` and exposes mixed answers containing both the correct answer and player bluffs.
+3. Final `submit_guess` auto-advances the session to `reveal` and returns the canonical reveal payload.
+4. The reveal payload includes:
+   - correct answer
+   - all lies
+   - all guesses
+   - fooled-player references for bluff hits
+5. The first canonical state read after reveal promotes the session to `scoreboard`.
+6. Scoreboard promotion preserves the same reveal payload and exposes a leaderboard with `scoreboard_ready=true`.
+
+## Artifact shape
+
+When `--artifact` is provided, the JSON file records:
+
+- the exact smoke command
+- session code and round question id
+- deterministic guess plan used to produce both bluff hits and one correct guess
+- per-step evidence for:
+  - `create_session`
+  - `join_players`
+  - `start_round`
+  - `auto_guess_transition`
+  - `submit_guesses`
+  - `auto_reveal_transition`
+  - `auto_scoreboard_transition`
+  - `finish_game`
+- reveal summary (`correct_answer`, lie/guess counts, fooled-player ids, correct guess player ids)
+- promoted scoreboard leaderboard payload
+
+## Targeted test coverage
+
+Backend regression coverage lives in `lobby/tests.py`:
+
+- `test_smoke_staging_command_runs_full_flow`
+- `test_smoke_staging_writes_phase_evidence_artifact_when_requested`
+
+Together they ensure the command stays runnable in normal workflow and that the evidence artifact contains phase-by-phase proof instead of only a generic pass/fail.
+
+Refs #287 #302

docs/ISSUE-310-HOST-TRANSITION-IDEMPOTENCY-ARTIFACT.md

@@ -0,0 +1,33 @@
+# Issue #310 — Host transition idempotency and error catalog
+
+## Scope
+
+This artifact hardens the two host-owned scoreboard exits in the canonical gameplay flow:
+
+- `POST /lobby/sessions/{code}/rounds/next`
+- `POST /lobby/sessions/{code}/finish`
+
+The goal is retry-safe host behavior when the scoreboard transition already succeeded server-side but the client retries because of a duplicate click, timeout, or lost response.
+
+## Transition contract
+
+| Endpoint | First valid transition | Idempotent replay state | Replay result | Broadcast behavior | Still-invalid states |
+|---|---|---|---|---|---|
+| `POST /lobby/sessions/{code}/rounds/next` | `scoreboard -> lie` | `lie` with persisted current-round bootstrap (`RoundConfig` + `RoundQuestion`) | `200 OK` with the same canonical next-round payload shape | `phase.lie_started` fires only on the first transition | `lobby`, `guess`, `reveal`, `finished` → `next_round_invalid_phase` |
+| `POST /lobby/sessions/{code}/finish` | `scoreboard -> finished` | `finished` | `200 OK` with the same final leaderboard payload shape | `phase.game_over` fires only on the first transition | `lobby`, `lie`, `guess`, `reveal` → `finish_game_invalid_phase` |
+
+## Error catalog notes
+
+No new backend error codes were introduced for this slice.
+
+The contract change is behavioral:
+
+- `next_round_invalid_phase` now means the session is in a phase where the scoreboard → next-round transition has **not** already been completed, or the expected bootstrap artifact for the already-started round is missing.
+- `finish_game_invalid_phase` now means the session is in a phase where the scoreboard → finish transition has **not** already been completed.
+- Successful replays are returned as normal `200 OK` canonical responses instead of phase errors.
+
+## Acceptance evidence
+
+- Repeated `rounds/next` calls after a successful scoreboard exit return the same canonical lie/bootstrap payload without incrementing the round twice.
+- Repeated `finish` calls after a successful scoreboard exit return the same finished leaderboard payload without rebroadcasting game-over.
+- Wrong-phase calls outside those replay states still return the existing shared error codes.

docs/ISSUE-312-LOBBY-FUPOGFAKTA-EXTRACTION-MAP.md

@@ -0,0 +1,202 @@
+# Issue #312 — FupOgFakta extraction map for logic currently living in `lobby/`
+
+Parent: #311  
+Issue: #312
+
+## Purpose
+
+This artifact documents the concrete FupOgFakta-specific logic that still lives in `lobby/`, separates it from true platform/session concerns, and names the intended destination ownership before any larger code move happens.
+
+It is intentionally an inventory + extraction plan only. It does **not** perform the full move.
+
+## Architectural boundary this map is enforcing
+
+The target boundary is already described in:
+
+- `docs/plans/2026-03-09-fupogfakta-game-engine-design.md`
+- `docs/plans/2026-03-09-fupogfakta-implementation-plan.md`
+- `docs/ARCHITECTURE.md`
+
+Those docs consistently describe:
+
+- `lobby/` as the **platform layer** for session lifecycle, player presence, host ownership, generic game-run orchestration, and transport-facing platform concerns.
+- `fupogfakta/` as the **game cartridge** that owns question selection rules, round config semantics, lie/guess/reveal/scoreboard flow, answer mixing, scoring, and game-specific response/event payloads.
+
+In other words:
+
+- **Platform (`lobby/`)** should know that a session exists and that a game can be started/observed.
+- **Cartridge (`fupogfakta/`)** should know what a lie is, what a guess is, how answers are mixed, when phases advance, and what payload shape those game phases expose.
+
+## Summary split
+
+### Generic platform/session concerns that belong in `lobby/`
+
+These are not FupOgFakta-specific and should remain platform-owned:
+
+- Session code parsing/generation:
+  - `lobby/views.py::_generate_session_code`
+  - `lobby/views.py::_normalize_session_code`
+  - `lobby/views.py::_create_unique_session_code`
+- Generic request parsing:
+  - `lobby/views.py::_json_body`
+- Session lifecycle and player presence endpoints:
+  - `lobby/views.py::create_session`
+  - `lobby/views.py::join_session`
+  - `lobby/views.py::session_detail` **only for the generic session/player shell part**
+- Generic ownership / host authorization checks
+- Generic session detail payload fields:
+  - `session.code`
+  - `session.status`
+  - `session.host_id`
+  - `session.current_round`
+  - `session.players_count`
+  - `players[].id|nickname|score|is_connected`
+- Generic i18n/error transport helper usage:
+  - `lobby/i18n.py`
+  - `api_error(...)`
+- Route mounting / namespace ownership in `lobby/urls.py` for platform routes only
+
+### FupOgFakta-specific logic currently misplaced in `lobby/`
+
+These items are game-cartridge logic and should move behind `fupogfakta/` ownership:
+
+- Round question selection by category and previously-used questions
+- Lie-phase payload construction and lie timer semantics
+- Mixed-answer preparation for bluff gameplay
+- Guess correctness / fooled-player detection
+- Bluff/correct-answer score resolution
+- Reveal payload construction
+- Reveal → scoreboard promotion rules
+- Start round / mix answers / submit lie / submit guess / calculate scores / reveal scoreboard / next round / finish game gameplay endpoints
+- Phase view-model booleans that encode FupOgFakta rules rather than generic platform readiness
+
+## Extraction map
+
+| Source file | Current function / concern | Why it is FupOgFakta-specific | Intended destination / owner |
+| --- | --- | --- | --- |
+| `lobby/views.py` | `_build_player_ref(player)` | Helper is only used to shape FupOgFakta reveal payloads; not a generic platform concern today. | `fupogfakta/serializers.py` or `fupogfakta/payloads.py` owned by cartridge. |
+| `lobby/views.py` | `_build_reveal_payload(round_question)` | Encodes FupOgFakta reveal contract: lies, guesses, fooled-player refs, correct answer, prompt. | `fupogfakta/payloads.py::build_reveal_payload` or equivalent cartridge response builder. |
+| `lobby/views.py` | `_build_leaderboard(session)` | Current implementation is generic-ish, but used exclusively by FupOgFakta scoreboard/finish flow and coupled to that response shape. | Short term: keep shared helper if multiple games will consume same contract; otherwise move to `fupogfakta/payloads.py` until a true shared scoreboard contract exists. |
+| `lobby/views.py` | `_get_current_round_question(session)` | Depends on FupOgFakta `RoundQuestion` model and current-round semantics. | `fupogfakta/services/rounds.py` or `fupogfakta/queries.py`. |
+| `lobby/views.py` | `_select_round_question(session, round_config)` | Implements FupOgFakta question selection rules by category, active questions, and not-yet-used question set. | `fupogfakta/services/rounds.py::select_round_question`. |
+| `lobby/views.py` | `_build_lie_started_payload(session, round_config, round_question)` | Builds a FupOgFakta event/response contract for lie phase, including category, prompt, lie deadline, round question id. | `fupogfakta/payloads.py::build_lie_started_payload`. |
+| `lobby/views.py` | `_prepare_mixed_answers(round_question)` | Bluff-answer dedupe and shuffle is core FupOgFakta gameplay logic. | `fupogfakta/services/answers.py::prepare_mixed_answers`. |
+| `lobby/views.py` | `_resolve_scores(session, round_question, round_config)` | Applies FupOgFakta scoring rules for correct guesses and successful bluffs; depends on `Guess`, `LieAnswer`, `ScoreEvent`, `points_correct`, `points_bluff`. | `fupogfakta/services/scoring.py::resolve_scores`. |
+| `lobby/views.py` | `_maybe_promote_reveal_to_scoreboard(session)` | Encodes FupOgFakta reveal completion semantics and scoreboard transition trigger. | `fupogfakta/services/phases.py::maybe_promote_reveal_to_scoreboard`. |
+| `lobby/views.py` | `_build_phase_view_model(session, players_count, has_round_question)` | Most booleans are not platform-generic; they encode FupOgFakta phase names (`lie`, `guess`, `scoreboard`) and MVP constraints (`3-5 players`, round-question readiness, next-round/finish gating). | Split: keep platform-shell fields in `lobby/`; move game-specific readiness/action flags to `fupogfakta/payloads.py::build_phase_view_model` or cartridge driver payload builder. |
+| `lobby/views.py` | `start_round(request, code)` | Starts FupOgFakta round, binds category, creates `RoundConfig`, selects `RoundQuestion`, transitions to `LIE`, broadcasts `phase.lie_started`. | `fupogfakta/views.py` or cartridge command handler behind a future `GameDriver.on_game_start` / round bootstrap service. |
+| `lobby/views.py` | `show_question(request, code)` | Emits lie-phase question payload using FupOgFakta `RoundQuestion` and `RoundConfig`. | `fupogfakta/views.py` or remove entirely once canonical driver flow owns the transition. |
+| `lobby/views.py` | `submit_lie(request, code, round_question_id)` | Pure FupOgFakta gameplay endpoint: lie validation, deadline semantics, auto-advance to guess phase, `phase.guess_started` payload. | `fupogfakta/views.py::submit_lie` (or cartridge intent handler). |
+| `lobby/views.py` | `mix_answers(request, code, round_question_id)` | Manual FupOgFakta host action for lie→guess transition and answer mixing. | `fupogfakta/views.py` short term; long term likely deleted in favor of cartridge-driven automatic transition. |
+| `lobby/views.py` | `submit_guess(request, code, round_question_id)` | Pure FupOgFakta gameplay endpoint: validates answer choice, resolves correctness/bluff source, auto-calculates scores, transitions to reveal. | `fupogfakta/views.py::submit_guess` plus `fupogfakta/services/scoring.py` and `fupogfakta/services/phases.py`. |
+| `lobby/views.py` | `reveal_scoreboard(request, code)` | FupOgFakta reveal/scoreboard progression, not a generic platform capability. | `fupogfakta/views.py::reveal_scoreboard` or cartridge phase service. |
+| `lobby/views.py` | `start_next_round(request, code)` | FupOgFakta next-round bootstrap: copies prior `RoundConfig`, increments round, picks next question, re-enters lie phase. | `fupogfakta/services/rounds.py::start_next_round` plus cartridge-owned endpoint/driver integration. |
+| `lobby/views.py` | `finish_game(request, code)` | Current finish path is tied to FupOgFakta scoreboard semantics and winner payload. | `fupogfakta/views.py::finish_game` until a truly generic platform finish contract exists. |
+| `lobby/views.py` | `calculate_scores(request, code, round_question_id)` | Explicit FupOgFakta score resolution endpoint. | `fupogfakta/services/scoring.py` and/or remove when fully absorbed by cartridge phase driver. |
+| `lobby/urls.py` | Gameplay routes for rounds, lies, guesses, scoreboard, finish | These route names expose FupOgFakta-specific phase/actions from the platform namespace. | Re-home under `fupogfakta/urls.py` or leave mounted under `/lobby/sessions/...` only as a temporary façade delegating to cartridge-owned code. |
+| `lobby/tests.py` | `StartRoundTests`, `LieSubmissionTests`, `MixAnswersTests`, `GuessSubmissionTests`, `CanonicalRoundFlowTests`, `ScoreCalculationTests`, `RevealRoundFlowTests`, `SessionDetailRoundQuestionTests`, `SessionDetailPhaseViewModelTests`, `SmokeStagingCommandTests` | These test classes verify FupOgFakta game flow rather than platform mechanics. | Move/split into `fupogfakta/tests/` with only session creation/join/platform transport tests left in `lobby/tests.py`. |
+| `lobby/management/commands/smoke_staging.py` | End-to-end gameplay smoke through lies/guesses/finish | Script executes one concrete game flow and should be cartridge-aware, not platform-owned. | `fupogfakta/management/commands/` or a shared smoke harness that delegates into cartridge-specific scenario runners. |
+
+## Recommended ownership split by module
+
+### Keep in `lobby/`
+
+- Session creation/join and session-code lifecycle
+- Generic player membership/presence reads
+- Generic auth/host checks helpers (if extracted from views)
+- Generic API error/i18n plumbing
+- Future `GameRun` / driver orchestration, timers, and cartridge dispatch
+- A slim generic `session_detail` envelope that can embed cartridge payloads under a dedicated game key
+
+### Move to `fupogfakta/`
+
+- Round state queries
+- Question selection
+- Lie/guess/reveal/scoreboard/finish transition rules
+- Score calculation
+- Answer mixing
+- Gameplay payload/response builders
+- Gameplay endpoints and tests
+- Gameplay smoke command
+
+## Explicit boundary for `session_detail`
+
+`session_detail` is currently mixed.
+
+### Generic part that should remain platform-owned
+
+- Session identity/status metadata
+- Player list / presence list
+- Generic host/player capability envelope if it is game-agnostic
+
+### FupOgFakta part that should move or be delegated
+
+- `round_question` payload
+- `reveal` payload
+- `scoreboard` payload
+- `phase_view_model` fields keyed to `lie`, `guess`, `scoreboard`, `finished`, `question_ready`, and 3–5-player MVP rules
+
+A clean future shape would be:
+
+```json
+{
+  "session": {"code": "ABC123", "status": "active", "game_type": "fupogfakta"},
+  "players": [...],
+  "game": {
+    "phase": "lie",
+    "payload": {"round_question": {...}, "reveal": null, "scoreboard": null}
+  }
+}
+```
+
+That makes `lobby/` the shell and `fupogfakta/` the authority for game-state payloads.
+
+## Concrete extraction sequence
+
+1. **Move pure helpers first**
+   - `_get_current_round_question`
+   - `_select_round_question`
+   - `_prepare_mixed_answers`
+   - `_resolve_scores`
+   - `_build_lie_started_payload`
+   - `_build_reveal_payload`
+2. **Move gameplay endpoints behind cartridge-owned service functions**
+   - `submit_lie`
+   - `submit_guess`
+   - `start_round`
+   - `start_next_round`
+   - `finish_game`
+   - `reveal_scoreboard`
+   - `calculate_scores`
+3. **Slim `session_detail` into platform envelope + delegated cartridge payload**
+4. **Move gameplay tests out of `lobby/tests.py`**
+5. **Optionally leave compatibility routes in `lobby/urls.py` as a façade** until clients are rewired
+
+## Risks this map is explicitly preventing
+
+- Moving only models but leaving hidden phase-transition rules in `lobby/views.py`
+- Treating `session_detail` as platform-generic while it still leaks cartridge payload semantics
+- Leaving scoreboard/reveal transition logic behind as an undocumented coupling
+- Splitting tests incorrectly so regressions stay "green" in `lobby/` while FupOgFakta behavior silently drifts
+
+## Decision
+
+For #311 / #312, the repository should treat the following as **game-specific and extraction candidates**:
+
+- round-question selection
+- lie/guess/reveal/scoreboard/finish transitions
+- answer mixing
+- score resolution
+- reveal/scoreboard payload builders
+- FupOgFakta-specific session-detail subpayloads
+- gameplay flow tests and smoke command
+
+And it should treat the following as **platform-generic**:
+
+- session identity/lifecycle
+- player presence/membership
+- host authorization shell
+- generic error transport
+- future game-driver dispatch/orchestration
+
+That is the explicit `lobby` vs `fupogfakta` boundary this issue needs before code extraction proceeds.

docs/STAGING_GAMEPLAY_SMOKE_ARTIFACT.md

@@ -23,11 +23,14 @@ Formål: levere et lille, ensartet evidensformat for release-nær gameplay-smoke
 - Active category/questions present: <yes/no>
 - Participants: host + <N> players
 - `USE_SPA_UI`: <on/off>
+- `WPP_SPA_ASSET_VERSION`: <release-token/sha>
 - UI route used:
   - OFF (legacy): `/lobby/ui/host` + `/lobby/ui/player`
   - ON (SPA shell): `/lobby/ui/host/<spa-path>` + `/lobby/ui/player`
 
 #### Checks (PASS/FAIL)
+0. Same release-window verification
+   - OFF + ON smoke kørt i samme release-vindue: <pass/fail>
 1. Cutover route sanity
    - Flag OFF serves legacy UI templates: <pass/fail>
    - Flag ON serves SPA shell on expected path(s): <pass/fail>
@@ -39,6 +42,19 @@ Formål: levere et lille, ensartet evidensformat for release-nær gameplay-smoke
    - next round transitions: <pass/fail>
    - final leaderboard visible: <pass/fail>
 
+#### Smoke-gate decision (før `USE_SPA_UI=true`)
+- Gate status: <GREEN/RED>
+- Gate criteria met:
+  - [ ] Cutover route sanity = PASS (OFF + ON)
+  - [ ] Full gameplay round = PASS
+  - [ ] Next-round/final leaderboard sanity = PASS
+  - [ ] Ingen nye blocker-regressioner i host/player flow
+
+#### Rollback checkpoint
+- Rollback required: <yes/no>
+- Trigger reason (if yes): <kort trigger>
+- Rollback done (`USE_SPA_UI=false`) verified: <yes/no>
+
 #### Evidence pointers
 - Command(s): `<exact command(s)>`
 - UI notes/screenshots/log refs: <short refs>

docs/UI_SMOKE.md

@@ -20,4 +20,29 @@
 9. Host: Beregn score og Vis scoreboard.
 10. Host: Næste runde eller Afslut spil.
 
+## Smoke-gate (staging cutover)
+`USE_SPA_UI` må kun aktiveres i staging når følgende er opfyldt:
+- Cutover route sanity er PASS for både OFF (legacy) og ON (SPA shell).
+- Én fuld gameplay-runde til scoreboard er PASS.
+- Next-round/final leaderboard sanity er PASS.
+- Ingen nye blocker-regressioner i host/player kerneflow.
+
+## Samme release-vindue: SPA OFF + ON verifikation
+Kør begge checks i samme release-vindue (samme deploy/artifact version):
+
+1. **OFF-pass (legacy)**
+   - `USE_SPA_UI=false`
+   - Verificér legacy routes + fuld runde.
+2. **ON-pass (SPA)**
+   - `USE_SPA_UI=true`
+   - Behold samme release artifact og kun toggl flag/version-token ved behov.
+   - Verificér SPA shell routes + fuld runde.
+3. Dokumentér begge pass i samme smoke-artifact med UTC timestamps og `WPP_SPA_ASSET_VERSION`.
+
+## Rollback check points
+Skift straks tilbage til `USE_SPA_UI=false` hvis en gate fejler:
+1. Verificér legacy routes (`/lobby/ui/host` + `/lobby/ui/player`) fungerer igen.
+2. Log rollback trigger + kort repro i smoke artifact.
+3. Opret/link blocker issue før nyt cutover-forsøg.
+
 Resultat: En fuld runde kan køres uden rå API-kald fra terminal.

docs/artifacts/issue-302-canonical-loop-smoke.json

@@ -0,0 +1,110 @@
+{
+  "ok": true,
+  "command": "python manage.py smoke_staging --artifact <path>",
+  "generated_at": "2026-03-16T15:19:30.105231+00:00",
+  "question": {
+    "prompt": "Smoke prompt?",
+    "correct_answer": "Correct"
+  },
+  "steps": [
+    {
+      "step": "create_session",
+      "session_status": "lobby"
+    },
+    {
+      "step": "join_players",
+      "players_count": 3
+    },
+    {
+      "step": "start_round",
+      "session_status": "lie",
+      "round_question_id": 1
+    },
+    {
+      "step": "auto_guess_transition",
+      "session_status": "guess",
+      "answers": [
+        "Lie from P3",
+        "Lie from P1",
+        "Lie from P2",
+        "Correct"
+      ]
+    },
+    {
+      "step": "submit_guesses",
+      "guess_results": [
+        {
+          "player_id": 1,
+          "selected_text": "Lie from P2",
+          "is_correct": false,
+          "fooled_player_id": 2
+        },
+        {
+          "player_id": 2,
+          "selected_text": "Correct",
+          "is_correct": true,
+          "fooled_player_id": null
+        },
+        {
+          "player_id": 3,
+          "selected_text": "Lie from P1",
+          "is_correct": false,
+          "fooled_player_id": 1
+        }
+      ]
+    },
+    {
+      "step": "auto_reveal_transition",
+      "session_status": "reveal",
+      "reveal": {
+        "correct_answer": "Correct",
+        "lies_count": 3,
+        "guesses_count": 3,
+        "fooled_player_ids": [
+          1,
+          2
+        ],
+        "correct_guess_player_ids": [
+          2
+        ]
+      }
+    },
+    {
+      "step": "auto_scoreboard_transition",
+      "session_status": "scoreboard",
+      "leaderboard": [
+        {
+          "id": 2,
+          "nickname": "P2",
+          "score": 7
+        },
+        {
+          "id": 1,
+          "nickname": "P1",
+          "score": 2
+        },
+        {
+          "id": 3,
+          "nickname": "P3",
+          "score": 0
+        }
+      ]
+    },
+    {
+      "step": "finish_game",
+      "session_status": "finished"
+    }
+  ],
+  "session_code": "7YV59E",
+  "players": [
+    "P1",
+    "P2",
+    "P3"
+  ],
+  "round_question_id": 1,
+  "guess_plan": {
+    "P1": "Lie from P2",
+    "P2": "Correct",
+    "P3": "Lie from P1"
+  }
+}

docs/i18n-drift-check.md

@@ -0,0 +1,34 @@
+# i18n key manifest + drift check
+
+Issue: #240
+
+This repo keeps shared lobby keyspaces in two files:
+
+- Contract source: `shared/i18n/lobby.json`
+- Key manifest: `shared/i18n/key-manifest.json`
+
+The manifest is intentionally small and explicit. It lists:
+
+- Supported locales (`locales`)
+- Frontend error key set (`frontend_error_keys`)
+- Backend error code set (`backend_error_codes`)
+- Backend translation key set (`backend_error_keys`)
+- Optional contract-only aliases (`allowed_contract_only_backend_codes`)
+
+## Local check
+
+Run the read-only drift checker from repo root:
+
+```bash
+python3 scripts/check_i18n_drift.py
+```
+
+The script returns non-zero when it detects drift, including:
+
+- key set mismatch between manifest and shared catalog
+- missing backend→frontend mapping coverage
+- mapping to unknown frontend keys
+- mappings for unknown backend codes
+- missing/empty locale translations (`en`/`da`)
+
+No CI gating changes are included in this task; this is a local guardrail.

docs/i18n-keymap.md

@@ -0,0 +1,69 @@
+# i18n key-map bootstrap (Angular host/player MVP)
+
+Issue: #220  
+Scope: Lobby → Join → Start round → Round → Reveal → Scoreboard  
+Locales: `en`, `da`
+
+This document is the gameplay key-namespace map for Angular host/player MVP.
+It maps existing text keys only (no feature expansion) and stays aligned with `shared/i18n/lobby.json`.
+
+## Key families
+
+- `host` — `frontend.ui.host.*` host-facing gameplay actions and status text.
+- `player` — `frontend.ui.player.*` player-facing gameplay actions and status text.
+- `system` — shared UI labels used across host/player views (implemented under `frontend.ui.common.*` in `shared/i18n/lobby.json`).
+- `errors` — user-facing error keys shown by frontend (`frontend.errors.*`) plus backend code → frontend key bridge via `backend.error_codes.*` / `contract.backend_to_frontend_error_keys.*`.
+
+## Gameplay flow key map
+
+| Flow step | Family | Key | en | da |
+|---|---|---|---|---|
+| Lobby | `host` | `host.title` | Host gameplay flow | Vært gameplay-flow |
+| Lobby | `player` | `player.title` | Player gameplay flow | Spiller gameplay-flow |
+| Lobby | `system` (`frontend.ui.common`) | `common.session_code` | Session code | Sessionskode |
+| Lobby | `player` | `player.nickname` | Nickname | Kaldenavn |
+| Join | `player` | `player.join` | Join | Join |
+| Start round | `host` | `host.start_round` | Start round | Start runde |
+| Round | `host` | `host.show_question` | Show question | Vis spørgsmål |
+| Round | `player` | `player.lie_label` | Lie | Løgn |
+| Round | `player` | `player.submit_lie` | Submit lie | Send løgn |
+| Round | `player` | `player.submit_guess` | Submit guess | Send gæt |
+| Reveal | `host` | `host.mix_answers` | Mix answers → guess | Bland svar → gæt |
+| Reveal | `host` | `host.calculate_scores` | Calculate scores → reveal | Udregn score → afslør |
+| Scoreboard | `host` | `host.load_scoreboard` | Load scoreboard | Hent scoreboard |
+| Scoreboard | `host` | `host.final_leaderboard` | Final leaderboard | Finale leaderboard |
+| Scoreboard | `player` | `player.final_leaderboard` | Final leaderboard | Finale leaderboard |
+| Scoreboard | `system` (`frontend.ui.common`) | `common.points_short` | pts | point |
+
+## Frontend error keys used in flow scope
+
+| Error family | Key | en | da |
+|---|---|---|---|
+| Join | `frontend.errors.session_code_required` | Session code is required. | Sessionskoden er påkrævet. |
+| Join | `frontend.errors.session_not_found` | Session code is invalid or the session no longer exists. | Sessionskoden er ugyldig, eller sessionen findes ikke længere. |
+| Join | `frontend.errors.nickname_invalid` | Nickname must be between 2 and 40 characters. | Kaldenavn skal være mellem 2 og 40 tegn. |
+| Join | `frontend.errors.nickname_taken` | Nickname is already taken. | Kaldenavnet er allerede taget. |
+| Join | `frontend.errors.join_failed` | Join failed. Check code or nickname and try again. | Kunne ikke joine. Tjek kode eller kaldenavn og prøv igen. |
+| Start round | `frontend.errors.start_round_failed` | Could not start round. Refresh the lobby and try again. | Kunne ikke starte runden. Opdater lobbyen og prøv igen. |
+| Any | `frontend.errors.unknown` | Action failed. Refresh status and try again. | Handlingen fejlede. Opdater status og prøv igen. |
+
+## Backend→frontend mapping for gameplay errors
+
+Mapped in `contract.backend_to_frontend_error_keys` (source: `shared/i18n/lobby.json`):
+
+> Note: `host_only_action` is **not** part of the current shared contract mapping and is intentionally not listed here.
+
+- `session_code_required` → `session_code_required`
+- `nickname_invalid` → `nickname_invalid`
+- `session_not_found` → `session_not_found`
+- `session_not_joinable` → `join_failed`
+- `nickname_taken` → `nickname_taken`
+- `category_slug_required` → `start_round_failed`
+- `category_not_found` → `start_round_failed`
+- `round_start_invalid_phase` → `start_round_failed`
+- `round_already_configured` → `start_round_failed`
+
+## Notes
+
+- This is a bootstrap key-map doc for MVP mergeability.
+- The key/value source of truth remains `shared/i18n/lobby.json`.

docs/issue-180-flow-log.md

@@ -0,0 +1,28 @@
+# Issue #180 – SPA gameplay flow evidence
+
+## Flow log (host + player, no page reload)
+
+1. Host opens SPA host shell and loads scoreboard (`GET /lobby/sessions/{code}/scoreboard`).
+2. Host starts next round (`POST /lobby/sessions/{code}/rounds/next`).
+3. Host shell refreshes session state in-place (`GET /lobby/sessions/{code}`) and clears old scoreboard/final leaderboard payloads.
+4. Player shell performs periodic session refresh while online (3s cadence) and transitions from `scoreboard` to `lobby` without page reload.
+5. Host finishes game (`POST /lobby/sessions/{code}/finish`) and renders final leaderboard directly in SPA shell.
+6. Player shell reads `finished` state and renders final leaderboard in SPA (sorted by score).
+7. Error/retry paths available:
+   - Host: next-round and finish-game retry buttons with explicit error feedback.
+   - Player: reconnect + submit retry feedback.
+
+## Test output snapshot
+
+Command:
+
+```bash
+cd frontend/angular
+npm test -- --run src/app/features/host/host-shell.component.spec.ts src/app/features/player/player-shell.component.spec.ts
+```
+
+Result:
+
+- `host-shell.component.spec.ts`: 6 passed
+- `player-shell.component.spec.ts`: 7 passed
+- Total: 13 passed, 0 failed

docs/plans/2026-03-09-fupogfakta-game-engine-design.md

@@ -0,0 +1,272 @@
+# Design: Fup og Fakta — Game Engine & Platform Architecture
+
+**Date:** 2026-03-09
+**Status:** Approved
+
+---
+
+## Overview
+
+Build a working Fup og Fakta game (Fibbage-style) on top of a **pluggable game platform**. The platform handles sessions, players, WebSocket push, and Celery-driven timers. Each game is a self-contained **cartridge** that implements a shared driver interface and owns its own models, config, and phase logic.
+
+---
+
+## Platform Architecture
+
+```
+partyhub/     Django project — settings, Celery app, ASGI
+lobby/        Platform layer — sessions, players, GameRun, timer dispatch
+realtime/     WebSocket consumers (already built)
+fupogfakta/   Game cartridge #1
+future_game/  Game cartridge #N (same interface)
+```
+
+### Platform provides (`lobby/`)
+
+#### Models
+
+**`GameSession`** (exists, minor additions)
+- `game_type` (CharField) — e.g. `"fupogfakta"`
+- `host` (FK → User)
+- `code` (6-char session code)
+- `status` (LOBBY / ACTIVE / FINISHED)
+- `config_id` / `config_snapshot` — see Config section
+
+**`GameRun`** (new — ephemeral, deleted on game exit)
+- `session` (OneToOne → GameSession)
+- `current_state` (CharField — game-defined state string)
+- `phase_deadline` (DateTimeField, nullable)
+- `is_paused` (BooleanField, default False)
+- `paused_remaining_seconds` (FloatField, nullable)
+- `celery_task_id` (CharField, nullable)
+- `state_data` (JSONField) — game-specific snapshot for current phase
+
+**`Player`** (exists)
+- `session`, `nickname`, `score`, `session_token`, `is_connected`
+
+#### GameDriver interface
+
+Each cartridge implements:
+
+```python
+class GameDriver:
+    game_type: str                        # e.g. "fupogfakta"
+
+    def on_game_start(session, run, config) -> PhaseResult
+    def on_timer_expired(session, run, config) -> PhaseResult
+    def on_pause(session, run) -> None
+    def on_resume(session, run) -> None
+    def on_exit(session, run) -> None     # must clean up all game data
+    def get_ws_payload(state, state_data) -> dict
+```
+
+`PhaseResult` = `(next_state: str, duration_seconds: int | None, broadcast_payload: dict)`
+
+#### Celery task
+
+```python
+@app.task
+def handle_timer_expired(run_id: int, expected_state: str):
+    # If run no longer exists or state has changed → stale task, ignore
+    # Call driver.on_timer_expired(session, run, config)
+    # Apply PhaseResult: update run, broadcast via channel layer, schedule next task
+```
+
+`expected_state` prevents stale tasks from firing after pause/resume or manual state changes.
+
+#### REST endpoints (platform-level)
+
+- `POST /sessions/{code}/play` — start or resume
+- `POST /sessions/{code}/pause` — pause current phase timer
+- `POST /sessions/{code}/exit` — end game, delete GameRun + all game data
+
+---
+
+## Configuration System
+
+### Base config model (`partyhub/`)
+
+```python
+class BaseGameConfig(models.Model):
+    class Meta:
+        abstract = True
+
+    name = models.CharField(max_length=100)          # "Quick game", "Full evening"
+    user = models.ForeignKey(User, null=True, ...)    # null = system default
+    is_default = models.BooleanField(default=False)
+    created_at = models.DateTimeField(auto_now_add=True)
+```
+
+### Game-specific config (`fupogfakta/`)
+
+```python
+class FupOgFaktaConfig(BaseGameConfig):
+    num_rounds               = PositiveIntegerField(default=3)
+    questions_per_round      = PositiveIntegerField(default=3)
+    min_players              = PositiveIntegerField(default=2)
+    max_players              = PositiveIntegerField(default=8)
+    lie_seconds              = PositiveIntegerField(default=45)
+    guess_seconds            = PositiveIntegerField(default=30)
+    reveal_seconds_per_lie   = PositiveIntegerField(default=8)
+    scoreboard_recap_seconds = PositiveIntegerField(default=10)
+    # Escalating scoring per round (stored as arrays or separate fields)
+    points_correct           = JSONField(default=[1500, 3000, 4500])
+    points_bluff             = JSONField(default=[500, 1000, 1500])
+    # Reaction bonus (static, feeds post-game awards only)
+    reaction_bonus           = IntegerField(default=5)
+```
+
+### Default resolution at session start
+
+1. User has `is_default=True` row for this game type → use that
+2. System default (`user=null, is_default=True`) — set in Django admin
+3. Model field `default=` values (hardcoded)
+
+User can have **multiple named presets** (one-to-many). When starting a session they choose which to use (or it auto-selects their default). The chosen config's values are **snapshotted into `GameRun.state_data`** at game start — immutable for the life of the session.
+
+---
+
+## Fup og Fakta — Game States
+
+```
+LOBBY
+  │ (host presses Play)
+  ▼
+LIE_PHASE         timer: lie_seconds
+  │ (all submitted OR timer expires)
+  ▼
+GUESS_PHASE       timer: guess_seconds
+  │ (timer expires — no mercy)
+  ▼
+REVEAL_LIE_{n}    timer: reveal_seconds_per_lie  (one per lie with ≥1 guess)
+  │                    → score liar incrementally as each is shown
+  ▼
+REVEAL_TRUTH      timer: reveal_seconds_per_lie
+  │                    → score correct guessers
+  ▼
+SCOREBOARD_RECAP  timer: scoreboard_recap_seconds
+  │
+  ├─ more questions in round → back to LIE_PHASE (next question)
+  ├─ round done, more rounds → back to LIE_PHASE (next round, next category)
+  └─ all rounds done → POST_GAME_AWARDS
+       timer: configurable
+       → FINISHED (GameRun deleted, GameSession status = FINISHED)
+```
+
+---
+
+## Fup og Fakta — Phase Details
+
+### LIE_PHASE
+- Question shown to all clients via WebSocket (`phase.lie_started` event)
+- Players submit lie via `POST /fupogfakta/{code}/lie`
+- **If lie matches correct answer (case-insensitive):** return `error_code: lie_matches_correct_answer` — player prompted again, does not consume their submission
+- Anonymous to other players during this phase
+- `state_data` tracks: question id, round number, how many have submitted (for progress display on host screen)
+- Timer expires → transition to GUESS_PHASE regardless of how many submitted
+
+### GUESS_PHASE
+- Answers mixed (lies + truth, deduped) broadcast to all clients (`phase.guess_started`)
+- Players guess via `POST /fupogfakta/{code}/guess`
+- **After selecting:** player can react to other lies with 👍 😂 ❤️ etc. until timer expires. Cannot change guess.
+- Reactions stored in `LieReaction` model (player, lie, reaction_type)
+- Timer expires → transition to first REVEAL_LIE (or REVEAL_TRUTH if no lies had guesses)
+
+### REVEAL_LIE_{n}
+- One Celery task per lie to reveal (only lies with ≥1 guesser)
+- Broadcast: which lie, who wrote it, who guessed it (`phase.reveal_lie`)
+- Score awarded to liar: `points_bluff[round_index] × guesser_count`
+- Score broadcast immediately (`phase.score_delta`)
+- Skipped lies (0 guesses): not shown at all
+
+### REVEAL_TRUTH
+- Broadcast: correct answer, who guessed correctly (`phase.reveal_truth`)
+- Score awarded: `points_correct[round_index]` per correct guesser
+- Also show reaction totals on each lie during this phase
+
+### SCOREBOARD_RECAP
+- Full leaderboard broadcast (`phase.scoreboard`)
+- Auto-advances to next question, next round, or post-game
+
+### POST_GAME_AWARDS
+- Computed from `LieReaction` aggregate:
+  - "Most Hilarious Liar" — most 😂 reactions total
+  - "Most Beloved Lie" — most ❤️ reactions on a single lie
+  - etc. (extensible)
+- Broadcast as `phase.awards`
+- Then FINISHED → GameRun deleted, all session game data wiped
+
+---
+
+## Fup og Fakta — Models
+
+**Existing (keep):** `Category`, `Question`, `RoundQuestion`, `LieAnswer`, `Guess`
+
+**Remove:** `ScoreEvent` (no audit trail needed — game state is ephemeral)
+
+**New:**
+```python
+class LieReaction(models.Model):
+    lie      = ForeignKey(LieAnswer, on_delete=CASCADE)
+    player   = ForeignKey(Player, on_delete=CASCADE)
+    reaction = CharField(max_length=20)  # "laugh", "heart", "fire", etc.
+    created_at = auto_now_add
+    class Meta:
+        unique_together = [("lie", "player", "reaction")]
+```
+
+**Modify `RoundQuestion`:**
+- Add `reveal_order` (PositiveIntegerField, nullable) — set when GUESS_PHASE ends, determines reveal sequence
+
+---
+
+## Pause / Resume
+
+- **Pause:** compute `remaining = phase_deadline - now`, store in `paused_remaining_seconds`, set `is_paused=True`, revoke Celery task by `celery_task_id`
+- **Resume:** set `phase_deadline = now + paused_remaining_seconds`, schedule new Celery task, clear pause fields
+- Stale task guard: every Celery task checks `expected_state == run.current_state` before firing
+
+---
+
+## Host Controls (Session Owner Only)
+
+| Action | Effect |
+|--------|--------|
+| Play   | Starts game from LOBBY, or resumes from paused |
+| Pause  | Freezes current phase timer, broadcasts `phase.paused` |
+| Exit   | Ends game immediately, deletes GameRun + all game data |
+
+Cannot skip. Cannot manually advance phases.
+
+---
+
+## WebSocket Event Reference
+
+| Event | Triggered by | Payload |
+|-------|-------------|---------|
+| `phase.lie_started` | LIE_PHASE start | question prompt, deadline, round info |
+| `phase.lie_progress` | Each lie submitted | n_submitted / n_players (no names) |
+| `phase.guess_started` | GUESS_PHASE start | mixed answers, deadline |
+| `phase.reveal_lie` | REVEAL_LIE_{n} | lie text, author, guessers, score delta |
+| `phase.reveal_truth` | REVEAL_TRUTH | correct answer, correct guessers, score delta |
+| `phase.scoreboard` | SCOREBOARD_RECAP | full leaderboard |
+| `phase.awards` | POST_GAME_AWARDS | award winners |
+| `phase.paused` | Pause | remaining_seconds |
+| `phase.resumed` | Resume | new deadline |
+| `phase.game_over` | FINISHED | final leaderboard |
+
+---
+
+## Data Lifecycle
+
+All game session data (`GameRun`, `RoundQuestion`, `LieAnswer`, `Guess`, `LieReaction`, `Player`) is **deleted when host exits or game reaches FINISHED**. `GameSession` row is kept (with status=FINISHED) for the session code uniqueness constraint. `Category` and `Question` content is permanent.
+
+---
+
+## Not In Scope (This Implementation)
+
+- TTS / read-aloud (Fase 4, deferred)
+- Reconnect recovery after server restart (game is gone if server dies)
+- Spectator/viewer mode (post-MVP)
+- Rate limiting on endpoints (backlog)
+- Bulk question import (Fase 5)

docs/spa-cutover-flag.md

@@ -12,9 +12,88 @@ Sæt env var pr. miljø:
 Backward compatibility under cutover:
 - Hvis `USE_SPA_UI` ikke er sat, bruges `WPP_SPA_ENABLED` som fallback.
 
+## Static asset versioning/cache-busting (hardening)
+Formål: sikre at browser/proxy/CDN hurtigt henter ny SPA bundle i release-vinduet uden at kræve hard refresh.
+
+- `WPP_SPA_ASSET_BASE` peger fortsat på build-output (`/static/frontend/angular/browser`).
+- `WPP_SPA_ASSET_VERSION` injiceres i SPA shell URLs som query-param (`?v=<version>`).
+- Anbefalet værdi for `WPP_SPA_ASSET_VERSION`: release-tag eller kort commit SHA.
+- Ved rollback sættes `WPP_SPA_ASSET_VERSION` til den tidligere kendte stabile release-værdi.
+
+Eksempel (staging/prod env):
+
+```env
+USE_SPA_UI=true
+WPP_SPA_ASSET_BASE=/static/frontend/angular/browser
+WPP_SPA_ASSET_VERSION=rel-2026-03-01-bb82357
+```
+
+## Staging rollout-checkliste (`USE_SPA_UI`)
+1. **Baseline (flag OFF)**
+   - Bekræft at staging kører med `USE_SPA_UI=false`.
+   - Kør gameplay smoke på legacy routes (`/lobby/ui/host` + `/lobby/ui/player`).
+2. **Smoke-gate før aktivering (skal være grøn)**
+   - Cutover route sanity = PASS for både OFF og ON checks.
+   - Full gameplay round (join/start/round/scoreboard) = PASS.
+   - Next-round/final leaderboard sanity = PASS.
+   - Ingen nye blocker-regressioner i host/player kerneflow.
+3. **Kontrolleret aktivering i staging**
+   - Sæt `USE_SPA_UI=true` i staging miljøet.
+   - Kør smoke-flow igen med SPA-route-verifikation.
+4. **Post-cutover dokumentation**
+   - Log evidens med commit/head SHA, UTC timestamp og gate-status.
+
+## Rollback playbook (`USE_SPA_UI`) — mål: <10 min
+Rollback til legacy (`USE_SPA_UI=false`) udføres straks hvis et checkpoint fejler:
+- Forkert route/shell for valgt flag i cutover route sanity.
+- Gameplay smoke kan ikke gennemføres til scoreboard/final leaderboard.
+- Kritisk regression i host/player flow under smoke.
+
+Trin-for-trin:
+1. Sæt `USE_SPA_UI=false` i deploy-env.
+2. Sæt `WPP_SPA_ASSET_VERSION` til sidste stabile release-token.
+3. Deploy/reload app-processer.
+4. Verificér legacy routes: `/lobby/ui/host` + `/lobby/ui/player`.
+5. Kør hurtig smoke sanity (join/start/scoreboard path).
+6. Log UTC tid, trigger, release-token og resultat i smoke artifact.
+
+Target: rollback + sanity-verifikation inden for 10 minutter.
+
+## React fallback trigger-kriterier (kun delivery-blocking)
+Formål: React fallback må kun bruges som kortvarig leverings-sikring, når release ellers er blokeret.
+
+### Hvornår fallback er tilladt
+Alle punkter skal være opfyldt:
+1. **Delivery-blocking fejl i Angular SPA**
+   - Host/player kerneflow kan ikke leveres i release-vinduet (fx login/join/start/round/scoreboard stopper).
+2. **Ingen hurtig Angular-fix inden for release-vinduet**
+   - Teamet har vurderet at patch + verificering ikke kan nås sikkert i tide.
+3. **Rollback alene løser ikke leveringsbehovet**
+   - `USE_SPA_UI=false` (legacy) er enten utilstrækkelig for den konkrete leverance eller allerede verificeret som ikke tilstrækkelig.
+4. **Beslutning er eksplicit logget**
+   - Trigger, impact, UTC-tid, ansvarlig, issue/incident-reference og plan for tilbagevenden til Angular er dokumenteret i release/smoke artifact.
+
+### Scope-limits for fallback
+- Fallback omfatter kun **delivery-blocking host/player-paths**.
+- Ingen nye features, UX-forbedringer eller ikke-kritiske ændringer må bundtes ind i fallback.
+- Fallback er **midlertidig** og gælder kun for aktiv incident/release-vindue.
+- Når blocker er fjernet, skal miljøet tilbage på standard cutover-spor (Angular + `USE_SPA_UI` styring).
+
+### Ikke tilladt
+- Proaktiv fallback "for en sikkerheds skyld" uden aktiv blocker.
+- Brug af fallback til at omgå normale kvalitetsgates eller testkrav.
+- Langvarig drift i fallback-mode uden dokumenteret blocker og opfølgningsplan.
+
 ## Verifikation
 - Flag OFF: `UiScreenTests.test_legacy_templates_are_used_when_spa_flag_is_off`
 - Flag ON (host): `UiScreenTests.test_host_screen_can_render_angular_shell_when_feature_flag_enabled`
 - Flag ON (host deep-link): `UiScreenTests.test_host_screen_deeplink_preserves_spa_path_when_feature_flag_enabled`
 - Flag ON (player): `UiScreenTests.test_player_screen_can_render_angular_shell_when_feature_flag_enabled`
 - Smoke-checkliste for cutover paths: `docs/STAGING_GAMEPLAY_SMOKE_ARTIFACT.md` + `docs/UI_SMOKE.md`
+
+
+## MVP audio policy guardrail (telefon-klient)
+- Telefon-/player-klienten må ikke starte lydafspilning lokalt i MVP (`primary-device only`).
+- Policy er bundet til capability-flaget `frontend.capabilities.client_has_no_audio_output=true` i `shared/i18n/lobby.json`.
+- Brugeradvarsel i player UI leveres via i18n key: `frontend.ui.player.audio_policy_notice`.
+- Acceptance-spec er dækket i Angular tests (`player-shell.component.spec.ts`), inkl. at init-path ikke kalder original media `play`.

frontend/angular/src/app/api-contract-smoke.spec.ts

@@ -0,0 +1,273 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import { createAngularApiClient, type AngularHttpClientLike } from '../../../src/api/angular-client';
+
+describe('SPA Angular API contract smoke (host/player foundation)', () => {
+  it('smoke-checks canonical host/player endpoint contracts', async () => {
+    const get = vi.fn<AngularHttpClientLike['get']>(async <T>(url: string) => {
+      if (url === '/lobby/sessions/ABCD12') {
+        return {
+          session: { code: 'ABCD12', status: 'lobby', host_id: 1, current_round: 1, players_count: 2 },
+          players: [
+            { id: 2, nickname: 'Maja', score: 0, is_connected: true },
+            { id: 3, nickname: 'Bo', score: 0, is_connected: true }
+          ],
+          round_question: {
+            id: 77,
+            round_number: 1,
+            prompt: 'Q?',
+            shown_at: '2026-03-01T18:00:00Z',
+            answers: [{ text: 'A' }, { text: 'B' }]
+          },
+          reveal: {
+            round_question_id: 77,
+            round_number: 1,
+            prompt: 'Q?',
+            correct_answer: 'A',
+            lies: [{ player_id: 2, nickname: 'Maja', text: 'B', created_at: '2026-03-01T18:00:05Z' }],
+            guesses: [
+              {
+                player_id: 3,
+                nickname: 'Bo',
+                selected_text: 'B',
+                is_correct: false,
+                fooled_player_id: 2,
+                fooled_player_nickname: 'Maja',
+                created_at: '2026-03-01T18:00:15Z'
+              }
+            ]
+          },
+          phase_view_model: {
+            status: 'lobby',
+            round_number: 1,
+            players_count: 2,
+            constraints: {
+              min_players_to_start: 2,
+              max_players_mvp: 8,
+              min_players_reached: true,
+              max_players_allowed: true
+            },
+            host: {
+              can_start_round: true,
+              can_show_question: false,
+              can_mix_answers: false,
+              can_calculate_scores: false,
+              can_reveal_scoreboard: false,
+              can_start_next_round: false,
+              can_finish_game: false
+            },
+            player: {
+              can_join: true,
+              can_submit_lie: false,
+              can_submit_guess: false,
+              can_view_final_result: false
+            }
+          }
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/scoreboard') {
+        return {
+          session: { code: 'ABCD12', status: 'scoreboard', current_round: 1 },
+          leaderboard: [
+            { id: 9, nickname: 'Maja', score: 200 },
+            { id: 10, nickname: 'Bo', score: 150 }
+          ]
+        } as T;
+      }
+
+      throw { status: 404, error: { error: 'Not found' } };
+    });
+
+    const post = vi.fn<AngularHttpClientLike['post']>(async <T>(url: string, body: unknown) => {
+      if (url === '/lobby/sessions/join') {
+        expect(body).toEqual({ code: 'ABCD12', nickname: 'Maja' });
+        return {
+          player: { id: 9, nickname: 'Maja', session_token: 'session-token-1', score: 0 },
+          session: { code: 'ABCD12', status: 'lobby' }
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/rounds/start') {
+        expect(body).toEqual({ category_slug: 'history' });
+        return {
+          session: { code: 'ABCD12', status: 'lie', current_round: 1 },
+          round: { number: 1, category: { slug: 'history', name: 'History' } }
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/questions/show') {
+        expect(body).toEqual({});
+        return {
+          round_question: {
+            id: 77,
+            prompt: 'Q?',
+            round_number: 1,
+            shown_at: '2026-03-01T18:00:00Z',
+            lie_deadline_at: '2026-03-01T18:00:30Z'
+          },
+          config: { lie_seconds: 30 }
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/questions/77/answers/mix') {
+        expect(body).toEqual({});
+        return {
+          session: { code: 'ABCD12', status: 'guess', current_round: 1 },
+          round_question: { id: 77, round_number: 1 },
+          answers: [{ text: 'A' }, { text: 'B' }]
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/questions/77/scores/calculate') {
+        expect(body).toEqual({});
+        return {
+          session: { code: 'ABCD12', status: 'reveal', current_round: 1 },
+          round_question: { id: 77, round_number: 1 },
+          events_created: 2,
+          reveal: {
+            round_question_id: 77,
+            correct_answer: 'A',
+            lies: [],
+            guesses: []
+          },
+          leaderboard: [
+            { id: 9, nickname: 'Maja', score: 200 },
+            { id: 10, nickname: 'Bo', score: 150 }
+          ]
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/rounds/next') {
+        expect(body).toEqual({});
+        return { session: { code: 'ABCD12', status: 'lie', current_round: 2 } } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/finish') {
+        expect(body).toEqual({});
+        return {
+          session: { code: 'ABCD12', status: 'finished', current_round: 2 },
+          winner: { id: 9, nickname: 'Maja', score: 250 },
+          leaderboard: [
+            { id: 9, nickname: 'Maja', score: 250 },
+            { id: 10, nickname: 'Bo', score: 150 }
+          ]
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/questions/77/lies/submit') {
+        expect(body).toEqual({ player_id: 9, session_token: 'session-token-1', text: 'my lie' });
+        return {
+          lie: {
+            id: 501,
+            player_id: 9,
+            round_question_id: 77,
+            text: 'my lie',
+            created_at: '2026-03-01T18:00:05Z'
+          },
+          window: { lie_deadline_at: '2026-03-01T18:00:30Z' }
+        } as T;
+      }
+
+      if (url === '/lobby/sessions/ABCD12/questions/77/guesses/submit') {
+        expect(body).toEqual({ player_id: 9, session_token: 'session-token-1', selected_text: 'B' });
+        return {
+          guess: {
+            id: 601,
+            player_id: 9,
+            round_question_id: 77,
+            selected_text: 'B',
+            is_correct: false,
+            fooled_player_id: null,
+            created_at: '2026-03-01T18:00:15Z'
+          },
+          window: { guess_deadline_at: '2026-03-01T18:01:00Z' }
+        } as T;
+      }
+
+      throw { status: 404, error: { error: 'Not found' } };
+    });
+
+    const client = createAngularApiClient({ get, post } as AngularHttpClientLike);
+
+    const session = await client.getSession(' abcd12 ');
+    expect(session.ok).toBe(true);
+    if (session.ok) {
+      expect(session.data.session.code).toBe('ABCD12');
+      expect(session.data.phase_view_model.host.can_start_next_round).toBe(false);
+      expect(session.data.phase_view_model.player.can_submit_guess).toBe(false);
+      expect(session.data.reveal?.correct_answer).toBe('A');
+      expect(session.data.reveal?.guesses[0].fooled_player_nickname).toBe('Maja');
+    }
+
+    expect((await client.joinSession({ code: ' abcd12 ', nickname: ' Maja ' })).ok).toBe(true);
+    expect((await client.startRound(' abcd12 ', { category_slug: 'history' })).ok).toBe(true);
+    expect((await client.showQuestion(' abcd12 ')).ok).toBe(true);
+    expect((await client.mixAnswers(' abcd12 ', 77)).ok).toBe(true);
+    expect((await client.calculateScores(' abcd12 ', 77)).ok).toBe(true);
+    expect((await client.getScoreboard(' abcd12 ')).ok).toBe(true);
+    expect((await client.startNextRound(' abcd12 ')).ok).toBe(true);
+    expect((await client.finishGame(' abcd12 ')).ok).toBe(true);
+    expect(
+      (
+        await client.submitLie(' abcd12 ', 77, {
+          player_id: 9,
+          session_token: 'session-token-1',
+          text: 'my lie'
+        })
+      ).ok
+    ).toBe(true);
+    expect(
+      (
+        await client.submitGuess(' abcd12 ', 77, {
+          player_id: 9,
+          session_token: 'session-token-1',
+          selected_text: 'B'
+        })
+      ).ok
+    ).toBe(true);
+
+    expect(get).toHaveBeenNthCalledWith(1, '/lobby/sessions/ABCD12', { withCredentials: true });
+    expect(get).toHaveBeenNthCalledWith(2, '/lobby/sessions/ABCD12/scoreboard', { withCredentials: true });
+
+    expect(post).toHaveBeenNthCalledWith(
+      1,
+      '/lobby/sessions/join',
+      { code: 'ABCD12', nickname: 'Maja' },
+      { withCredentials: true }
+    );
+    expect(post).toHaveBeenNthCalledWith(
+      2,
+      '/lobby/sessions/ABCD12/rounds/start',
+      { category_slug: 'history' },
+      { withCredentials: true }
+    );
+    expect(post).toHaveBeenNthCalledWith(3, '/lobby/sessions/ABCD12/questions/show', {}, { withCredentials: true });
+    expect(post).toHaveBeenNthCalledWith(
+      4,
+      '/lobby/sessions/ABCD12/questions/77/answers/mix',
+      {},
+      { withCredentials: true }
+    );
+    expect(post).toHaveBeenNthCalledWith(
+      5,
+      '/lobby/sessions/ABCD12/questions/77/scores/calculate',
+      {},
+      { withCredentials: true }
+    );
+    expect(post).toHaveBeenNthCalledWith(6, '/lobby/sessions/ABCD12/rounds/next', {}, { withCredentials: true });
+    expect(post).toHaveBeenNthCalledWith(7, '/lobby/sessions/ABCD12/finish', {}, { withCredentials: true });
+    expect(post).toHaveBeenNthCalledWith(
+      8,
+      '/lobby/sessions/ABCD12/questions/77/lies/submit',
+      { player_id: 9, session_token: 'session-token-1', text: 'my lie' },
+      { withCredentials: true }
+    );
+    expect(post).toHaveBeenNthCalledWith(
+      9,
+      '/lobby/sessions/ABCD12/questions/77/guesses/submit',
+      { player_id: 9, session_token: 'session-token-1', selected_text: 'B' },
+      { withCredentials: true }
+    );
+  });
+});

frontend/angular/src/app/app.component.css

@@ -1,4 +1,5 @@
 .shell { font-family: Arial, sans-serif; margin: 1rem; }
-.shell__header { display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid #ddd; padding-bottom: 0.75rem; }
+.shell__header { display: flex; flex-wrap: wrap; gap: 0.75rem; justify-content: space-between; align-items: center; border-bottom: 1px solid #ddd; padding-bottom: 0.75rem; }
 .shell__header nav { display: flex; gap: 0.75rem; }
 .shell__content { margin-top: 1rem; }
+.locale-picker { display: inline-flex; align-items: center; gap: 0.4rem; font-size: 0.95rem; }

frontend/angular/src/app/app.component.html

@@ -1,13 +1,20 @@
 <main class="shell">
   <header class="shell__header">
-    <h1>WPP Angular Shell</h1>
+    <h1>{{ copy('app.title') }}</h1>
     <nav>
-      <a routerLink="/host">Host</a>
-      <a routerLink="/player">Player</a>
+      <a routerLink="/host">{{ copy('app.host_nav') }}</a>
+      <a routerLink="/player">{{ copy('app.player_nav') }}</a>
     </nav>
+    <label class="locale-picker">
+      {{ copy('app.language_label') }}
+      <select [ngModel]="locale" (ngModelChange)="setLocale($event)">
+        <option value="en">English</option>
+        <option value="da">Dansk</option>
+      </select>
+    </label>
   </header>
 
-  <section class="shell__content">
+  <section class="shell__content" [attr.data-wpp-locale]="locale">
     <router-outlet></router-outlet>
   </section>
 </main>

frontend/angular/src/app/app.component.ts

@@ -1,20 +1,33 @@
 import { Component, inject } from '@angular/core';
+import { FormsModule } from '@angular/forms';
 import { Router, RouterLink, RouterOutlet } from '@angular/router';
 
+import { resolvePreferredLocale, setPreferredLocale, t } from './lobby-i18n';
+
 @Component({
   selector: 'app-root',
   standalone: true,
-  imports: [RouterOutlet, RouterLink],
+  imports: [RouterOutlet, RouterLink, FormsModule],
   templateUrl: './app.component.html',
   styleUrl: './app.component.css',
 })
 export class AppComponent {
   private readonly router = inject(Router);
 
+  locale = resolvePreferredLocale();
+
   constructor() {
     const shellRoute = document.body.dataset['wppShellRoute'];
     if (shellRoute?.startsWith('/host') || shellRoute?.startsWith('/player')) {
       void this.router.navigateByUrl(shellRoute);
     }
   }
+
+  copy(key: string): string {
+    return t(key, this.locale);
+  }
+
+  setLocale(locale: string): void {
+    this.locale = setPreferredLocale(locale);
+  }
 }

frontend/angular/src/app/app.config.ts

@@ -1,7 +1,15 @@
 import { ApplicationConfig } from '@angular/core';
 import { provideRouter, withHashLocation } from '@angular/router';
+
 import { routes } from './app.routes';
+import { createWppApiClient, WPP_API_CLIENT } from './wpp-api-client';
 
 export const appConfig: ApplicationConfig = {
-  providers: [provideRouter(routes, withHashLocation())],
+  providers: [
+    provideRouter(routes, withHashLocation()),
+    {
+      provide: WPP_API_CLIENT,
+      useFactory: () => createWppApiClient(),
+    },
+  ],
 };

frontend/angular/src/app/features/host/host-shell.component.spec.ts

@@ -4,6 +4,8 @@ import { HostShellComponent } from './host-shell.component';
 
 type FetchMock = ReturnType<typeof vi.fn>;
 
+type FetchRouteHandler = (input: RequestInfo | URL, init?: RequestInit) => Response | Promise<Response>;
+
 function jsonResponse(status: number, body: unknown) {
   return {
     ok: status >= 200 && status < 300,
@@ -12,7 +14,31 @@ function jsonResponse(status: number, body: unknown) {
   } as unknown as Response;
 }
 
-function sessionDetailPayload(status: string, options?: { roundQuestionId?: number | null }) {
+function createFetchRouteMock(handler: FetchRouteHandler): FetchMock {
+  return vi.fn((input: RequestInfo | URL, init?: RequestInit) => Promise.resolve(handler(input, init)));
+}
+
+function sessionDetailPayload(
+  status: string,
+  options?: {
+    currentPhase?: string;
+    roundQuestionId?: number | null;
+    reveal?: {
+      correct_answer: string;
+      prompt?: string;
+      lies?: Array<{ player_id: number; nickname: string; text: string; created_at?: string }>;
+      guesses?: Array<{
+        player_id: number;
+        nickname: string;
+        selected_text: string;
+        is_correct: boolean;
+        fooled_player_id: number | null;
+        fooled_player_nickname?: string;
+        created_at?: string;
+      }>;
+    } | null;
+  }
+) {
   const roundQuestionId = options?.roundQuestionId ?? 41;
 
   return {
@@ -37,8 +63,26 @@ function sessionDetailPayload(status: string, options?: { roundQuestionId?: numb
       { id: 1, nickname: 'Host', score: 0, is_connected: true },
       { id: 2, nickname: 'Mads', score: 120, is_connected: true },
     ],
+    reveal:
+      options?.reveal === undefined || options?.reveal === null
+        ? null
+        : {
+            round_question_id: roundQuestionId,
+            round_number: 1,
+            prompt: options.reveal.prompt ?? 'Q?',
+            correct_answer: options.reveal.correct_answer,
+            lies: (options.reveal.lies ?? []).map((lie) => ({
+              ...lie,
+              created_at: lie.created_at ?? '2026-01-01T00:00:05Z',
+            })),
+            guesses: (options.reveal.guesses ?? []).map((guess) => ({
+              ...guess,
+              created_at: guess.created_at ?? '2026-01-01T00:00:10Z',
+            })),
+          },
     phase_view_model: {
       status,
+      current_phase: options?.currentPhase ?? status,
       round_number: 1,
       players_count: 2,
       constraints: {
@@ -47,14 +91,18 @@ function sessionDetailPayload(status: string, options?: { roundQuestionId?: numb
         min_players_reached: true,
         max_players_allowed: true,
       },
+      readiness: {
+        question_ready: (options?.currentPhase ?? status) !== 'lobby',
+        scoreboard_ready: (options?.currentPhase ?? status) === 'reveal' || (options?.currentPhase ?? status) === 'scoreboard',
+      },
       host: {
-        can_start_round: status === 'lobby',
-        can_show_question: status === 'lie',
-        can_mix_answers: status === 'lie',
-        can_calculate_scores: status === 'guess',
-        can_reveal_scoreboard: status === 'reveal',
-        can_start_next_round: status === 'scoreboard',
-        can_finish_game: status === 'scoreboard',
+        can_start_round: (options?.currentPhase ?? status) === 'lobby',
+        can_show_question: (options?.currentPhase ?? status) === 'lie',
+        can_mix_answers: (options?.currentPhase ?? status) === 'lie' || (options?.currentPhase ?? status) === 'guess',
+        can_calculate_scores: (options?.currentPhase ?? status) === 'guess',
+        can_reveal_scoreboard: (options?.currentPhase ?? status) === 'reveal',
+        can_start_next_round: (options?.currentPhase ?? status) === 'scoreboard',
+        can_finish_game: (options?.currentPhase ?? status) === 'scoreboard',
       },
       player: {
         can_join: status === 'lobby',
@@ -101,54 +149,76 @@ describe('HostShellComponent gameplay wiring', () => {
     expect(component.loading).toBe(false);
   });
 
-  it('captures scoreboard error for retry path', async () => {
-    const fetchMock: FetchMock = vi.fn().mockResolvedValue(jsonResponse(500, { error: 'Scoreboard unavailable' }));
+  it('hydrates canonical reveal payload in reveal phase', async () => {
+    const fetchMock: FetchMock = vi.fn().mockResolvedValue(
+      jsonResponse(
+        200,
+        sessionDetailPayload('reveal', {
+          roundQuestionId: 77,
+          reveal: {
+            correct_answer: 'Mercury',
+            lies: [{ player_id: 2, nickname: 'Mads', text: 'Venus' }],
+            guesses: [
+              {
+                player_id: 3,
+                nickname: 'Luna',
+                selected_text: 'Venus',
+                is_correct: false,
+                fooled_player_id: 2,
+                fooled_player_nickname: 'Mads',
+              },
+            ],
+          },
+        })
+      )
+    );
 
     vi.stubGlobal('fetch', fetchMock);
 
     const component = new HostShellComponent();
     component.sessionCode = 'ABCD12';
 
-    await component.loadScoreboard();
+    await component.refreshSession();
 
-    expect(fetchMock).toHaveBeenCalledWith('/lobby/sessions/ABCD12/scoreboard', expect.objectContaining({ method: 'GET' }));
-    expect(component.scoreboardError).toContain('Scoreboard failed: Scoreboard unavailable');
-    expect(component.loading).toBe(false);
+    expect(component.session?.reveal?.correct_answer).toBe('Mercury');
+    expect(component.session?.reveal?.lies[0]).toMatchObject({ player_id: 2, nickname: 'Mads', text: 'Venus' });
+    expect(component.session?.reveal?.guesses[0]).toMatchObject({
+      player_id: 3,
+      nickname: 'Luna',
+      selected_text: 'Venus',
+      fooled_player_id: 2,
+      fooled_player_nickname: 'Mads',
+    });
   });
 
-  it('wires showQuestion, mixAnswers and calculateScores with expected request payloads', async () => {
-    const fetchMock: FetchMock = vi
-      .fn()
-      .mockResolvedValueOnce(
-        jsonResponse(200, {
-          round_question: {
-            id: 77,
-            round_number: 1,
-            prompt: 'Q?',
-            shown_at: '2026-01-01T00:00:00Z',
-            lie_deadline_at: '2026-01-01T00:00:45Z',
-          },
-          config: { lie_seconds: 45 },
-        })
-      )
-      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('lie', { roundQuestionId: 77 })))
-      .mockResolvedValueOnce(
-        jsonResponse(200, {
-          session: { code: 'ABCD12', status: 'guess', current_round: 1 },
-          round_question: { id: 77, round_number: 1 },
-          answers: [{ text: 'A' }],
-        })
-      )
-      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('guess', { roundQuestionId: 77 })))
-      .mockResolvedValueOnce(
-        jsonResponse(200, {
-          session: { code: 'ABCD12', status: 'reveal', current_round: 1 },
-          round_question: { id: 77, round_number: 1 },
-          events_created: 2,
-          leaderboard: [{ id: 1, nickname: 'Luna', score: 320 }],
-        })
-      )
-      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('reveal', { roundQuestionId: 77 })));
+  it('wires showQuestion, mixAnswers and calculateScores with canonical phase gating', async () => {
+    let refreshCount = 0;
+    const fetchMock = createFetchRouteMock((input, init) => {
+      const url = String(input);
+      const method = init?.method ?? 'GET';
+
+      if (method === 'POST' && url === '/lobby/sessions/ABCD12/questions/show') {
+        return jsonResponse(200, { session: { code: 'ABCD12', status: 'lie', current_round: 2 } });
+      }
+      if (method === 'POST' && url === '/lobby/sessions/ABCD12/questions/99/answers/mix') {
+        return jsonResponse(200, { session: { code: 'ABCD12', status: 'guess', current_round: 2 } });
+      }
+      if (method === 'POST' && url === '/lobby/sessions/ABCD12/questions/77/scores/calculate') {
+        return jsonResponse(200, { session: { code: 'ABCD12', status: 'reveal', current_round: 2 } });
+      }
+      if (method === 'GET' && url === '/lobby/sessions/ABCD12') {
+        refreshCount += 1;
+        if (refreshCount === 1) {
+          return jsonResponse(200, sessionDetailPayload('lie', { roundQuestionId: 99 }));
+        }
+        if (refreshCount === 2) {
+          return jsonResponse(200, sessionDetailPayload('guess', { roundQuestionId: 77 }));
+        }
+        return jsonResponse(200, sessionDetailPayload('reveal', { roundQuestionId: 77 }));
+      }
+
+      throw new Error(`Unhandled fetch in test: ${method} ${url}`);
+    });
 
     vi.stubGlobal('fetch', fetchMock);
 
@@ -156,19 +226,37 @@ describe('HostShellComponent gameplay wiring', () => {
     component.sessionCode = ' abcd12 ';
     component.roundQuestionId = ' 77 ';
 
+    component.session = sessionDetailPayload('lie', { roundQuestionId: null }) as any;
     await component.showQuestion();
+    expect(component.session?.session.status).toBe('lie');
+    expect(component.roundQuestionId).toBe('99');
+
+    component.session = sessionDetailPayload('guess', { roundQuestionId: 77 }) as any;
     await component.mixAnswers();
+    expect(component.session?.session.status).toBe('guess');
+
     await component.calculateScores();
 
+    expect(component.session?.session.status).toBe('reveal');
     expect(component.error).toBe('');
     expect(component.loading).toBe(false);
+    expect(fetchMock).toHaveBeenCalledTimes(6);
   });
 
   it('runs next-round transition without reload and clears scoreboard payload', async () => {
-    const fetchMock: FetchMock = vi
-      .fn()
-      .mockResolvedValueOnce(jsonResponse(200, { session: { code: 'ABCD12', status: 'lobby', current_round: 2 } }))
-      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('lobby', { roundQuestionId: null })));
+    const fetchMock = createFetchRouteMock((input, init) => {
+      const url = String(input);
+      const method = init?.method ?? 'GET';
+
+      if (method === 'POST' && url === '/lobby/sessions/ABCD12/rounds/next') {
+        return jsonResponse(200, { session: { code: 'ABCD12', status: 'lie', current_round: 2 } });
+      }
+      if (method === 'GET' && url === '/lobby/sessions/ABCD12') {
+        return jsonResponse(200, sessionDetailPayload('lie', { roundQuestionId: 99 }));
+      }
+
+      throw new Error(`Unhandled fetch in test: ${method} ${url}`);
+    });
 
     vi.stubGlobal('fetch', fetchMock);
 
@@ -177,6 +265,7 @@ describe('HostShellComponent gameplay wiring', () => {
     component.scoreboardPayload = '{"leaderboard":[]}';
     component.finalLeaderboardPayload = '{"leaderboard":[{"nickname":"Old","score":1}]}' ;
     component.finalLeaderboard = [{ id: 9, nickname: 'Old', score: 1 }];
+    component.session = sessionDetailPayload('scoreboard', { roundQuestionId: 77 }) as any;
 
     await component.startNextRound();
 
@@ -186,8 +275,8 @@ describe('HostShellComponent gameplay wiring', () => {
       expect.objectContaining({ method: 'POST', body: JSON.stringify({}) })
     );
     expect(fetchMock).toHaveBeenNthCalledWith(2, '/lobby/sessions/ABCD12', expect.objectContaining({ method: 'GET' }));
-    expect(component.session?.session.status).toBe('lobby');
-    expect(component.scoreboardPayload).toBe('');
+    expect(component.session?.session.status).toBe('lie');
+    expect(component.roundQuestionId).toBe('99');
     expect(component.finalLeaderboardPayload).toBe('');
     expect(component.finalLeaderboard).toEqual([]);
     expect(component.nextRoundError).toBe('');
@@ -213,6 +302,7 @@ describe('HostShellComponent gameplay wiring', () => {
 
     const component = new HostShellComponent();
     component.sessionCode = 'ABCD12';
+    component.session = sessionDetailPayload('scoreboard', { roundQuestionId: 77 }) as any;
 
     await component.finishGame();
     expect(component.finishError).toContain('Finish game failed: Final leaderboard timeout');
@@ -236,6 +326,7 @@ describe('HostShellComponent gameplay wiring', () => {
 
     const component = new HostShellComponent();
     component.sessionCode = '   ';
+    component.session = sessionDetailPayload('scoreboard', { roundQuestionId: 77 }) as any;
 
     await component.startNextRound();
     await component.finishGame();
@@ -245,20 +336,120 @@ describe('HostShellComponent gameplay wiring', () => {
     expect(component.finishError).toContain('Session code is required');
   });
 
-  it('bootstraps refresh from resolver route context on init', () => {
+  it('blocks illegal host actions outside canonical phase permissions', async () => {
+    const fetchMock: FetchMock = vi.fn();
+    vi.stubGlobal('fetch', fetchMock);
+
+    const component = new HostShellComponent();
+    component.sessionCode = 'ABCD12';
+    component.roundQuestionId = '77';
+
+    for (const status of ['guess', 'reveal', 'scoreboard'] as const) {
+      component.session = sessionDetailPayload(status, { roundQuestionId: 77 }) as any;
+      await component.showQuestion();
+    }
+
+    for (const status of ['lie', 'reveal', 'scoreboard'] as const) {
+      component.session = sessionDetailPayload(status, { roundQuestionId: 77 }) as any;
+      await component.calculateScores();
+    }
+
+    for (const status of ['lie', 'guess', 'scoreboard'] as const) {
+      component.session = sessionDetailPayload(status, { roundQuestionId: 77 }) as any;
+      await component.loadScoreboard();
+    }
+
+    for (const status of ['lie', 'guess', 'reveal'] as const) {
+      component.session = sessionDetailPayload(status, { roundQuestionId: 77 }) as any;
+      await component.startNextRound();
+      await component.finishGame();
+    }
+
+    component.session = sessionDetailPayload('guess', { roundQuestionId: 77 }) as any;
+    expect(component.canShowQuestion).toBe(false);
+
+    component.session = sessionDetailPayload('reveal', { roundQuestionId: 77 }) as any;
+    expect(component.canCalculateScores).toBe(false);
+    expect(component.canLoadScoreboard).toBe(true);
+    expect(component.canStartNextRound).toBe(false);
+    expect(component.canFinishGame).toBe(false);
+
+    component.session = sessionDetailPayload('scoreboard', { roundQuestionId: 77 }) as any;
+    expect(component.canLoadScoreboard).toBe(false);
+    expect(component.canStartNextRound).toBe(true);
+    expect(component.canFinishGame).toBe(true);
+    expect(fetchMock).not.toHaveBeenCalled();
+  });
+
+  it('prefers canonical current_phase for reveal panel and host routing when status lags behind', async () => {
+    const fetchMock: FetchMock = vi.fn().mockResolvedValue(
+      jsonResponse(200, sessionDetailPayload('reveal', { currentPhase: 'scoreboard', roundQuestionId: 77, reveal: { correct_answer: 'Mercury' } }))
+    );
+    vi.stubGlobal('fetch', fetchMock);
+
+    const replaceState = vi.fn();
     vi.stubGlobal('window', {
-      sessionStorage: {
-        getItem: vi.fn().mockReturnValue(null),
-        setItem: vi.fn(),
-      },
+      location: { hash: '#/host/reveal/ABCD12' },
+      history: { state: null, replaceState },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn() },
     });
 
-    const component = new HostShellComponent({ snapshot: { data: { routeContext: { sessionCode: 'ab12' } } } } as never);
-    const refreshSpy = vi.spyOn(component, 'refreshSession').mockResolvedValue();
+    const component = new HostShellComponent();
+    component.sessionCode = 'ABCD12';
 
-    component.ngOnInit();
+    await component.refreshSession();
 
-    expect(component.sessionCode).toBe('AB12');
-    expect(refreshSpy).toHaveBeenCalledOnce();
+    expect(component.gameplayPhase).toBe('scoreboard');
+    expect(component.showRevealPanel).toBe(true);
+    expect(component.canLoadScoreboard).toBe(false);
+    expect(component.canStartNextRound).toBe(true);
+    expect(component.canFinishGame).toBe(true);
+    expect(replaceState).toHaveBeenCalledWith(null, '', '#/host/scoreboard/ABCD12');
+  });
+
+  it('syncs host hash-route with latest phase after refresh without page reload', async () => {
+    const fetchMock: FetchMock = vi.fn().mockResolvedValue(jsonResponse(200, sessionDetailPayload('guess', { roundQuestionId: 77 })));
+    vi.stubGlobal('fetch', fetchMock);
+
+    const replaceState = vi.fn();
+    vi.stubGlobal('window', {
+      location: { hash: '#/host/lobby/ABCD12' },
+      history: { state: null, replaceState },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn() },
+    });
+
+    const component = new HostShellComponent();
+    component.sessionCode = 'ABCD12';
+
+    await component.refreshSession();
+
+    expect(replaceState).toHaveBeenCalledWith(null, '', '#/host/guess/ABCD12');
+    expect(component.canStartRound).toBe(false);
+    expect(component.canStartNextRound).toBe(false);
+    expect(component.canFinishGame).toBe(false);
+  });
+
+  it('uses phase_view_model to keep host action surface bound to round boundaries only', async () => {
+    const component = new HostShellComponent();
+
+    expect(component.canStartRound).toBe(true);
+    expect(component.canStartNextRound).toBe(false);
+    expect(component.canFinishGame).toBe(false);
+
+    component.session = sessionDetailPayload('lie') as any;
+    expect(component.canStartRound).toBe(false);
+    expect(component.canShowQuestion).toBe(true);
+    expect(component.canStartNextRound).toBe(false);
+    expect(component.canFinishGame).toBe(false);
+
+    component.session = sessionDetailPayload('reveal') as any;
+    expect(component.canLoadScoreboard).toBe(true);
+    expect(component.canStartNextRound).toBe(false);
+    expect(component.canFinishGame).toBe(false);
+
+    component.session = sessionDetailPayload('scoreboard') as any;
+    expect(component.canLoadScoreboard).toBe(false);
+    expect(component.canStartNextRound).toBe(true);
+    expect(component.canFinishGame).toBe(true);
   });
 });

frontend/angular/src/app/features/host/host-shell.component.ts

@@ -1,20 +1,16 @@
 import { CommonModule } from '@angular/common';
-import { Component, OnInit, Optional } from '@angular/core';
-import { ActivatedRoute } from '@angular/router';
+import { Component, OnDestroy, OnInit } from '@angular/core';
 import { FormsModule } from '@angular/forms';
 
 import { createApiClient } from '../../../../../src/api/client';
-import type { FinishGameResponse, ScoreboardResponse } from '../../../../../src/api/types';
+import type { FinishGameResponse, ScoreboardResponse, SessionDetailResponse } from '../../../../../src/api/types';
+import { deriveGameplayPhase, isHostGameplayActionAllowed } from '../../../../../src/spa/gameplay-phase-machine';
 import { createVerticalSliceController } from '../../../../../src/spa/vertical-slice';
-import type { RouteSessionContext } from '../../session-route-context';
+import { clientHasNoAudioOutput, resolvePreferredLocale, subscribeToLocaleChanges, t } from '../../lobby-i18n';
 
-interface SessionDetail {
-  session: { code: string; status: string; current_round: number };
-  round_question: { id: number; prompt: string; answers: Array<{ text: string }> } | null;
-  players: Array<{ id: number; nickname: string; score: number }>;
-}
+type SessionDetail = SessionDetailResponse;
 
-type LeaderboardEntry = ScoreboardResponse['leaderboard'][number];
+type LeaderboardEntry = FinishGameResponse['leaderboard'][number];
 type LeaderboardResponse = FinishGameResponse;
 
 @Component({
@@ -22,40 +18,61 @@ type LeaderboardResponse = FinishGameResponse;
   standalone: true,
   imports: [CommonModule, FormsModule],
   template: `
-    <h2>Host SPA gameplay flow</h2>
+    <h2>{{ copy('host.title') }}</h2>
 
-    <div class="panel">
-      <label>Session code <input [(ngModel)]="sessionCode" /></label>
-      <label>Category <input [(ngModel)]="categorySlug" /></label>
-      <button (click)="refreshSession()" [disabled]="loading">Refresh</button>
-      <button (click)="startRound()" [disabled]="loading">Start round</button>
-      <button (click)="showQuestion()" [disabled]="loading || !roundQuestionId">Show question</button>
-      <button (click)="mixAnswers()" [disabled]="loading || !roundQuestionId">Mix answers → guess</button>
-      <button (click)="calculateScores()" [disabled]="loading || !roundQuestionId">Calculate scores → reveal</button>
-      <button (click)="loadScoreboard()" [disabled]="loading">Load scoreboard</button>
-      <button (click)="startNextRound()" [disabled]="loading">Start next round</button>
-      <button (click)="finishGame()" [disabled]="loading">Finish game</button>
-      <button *ngIf="scoreboardError" (click)="loadScoreboard()" [disabled]="loading">Retry scoreboard</button>
-      <button *ngIf="nextRoundError" (click)="startNextRound()" [disabled]="loading">Retry next round</button>
-      <button *ngIf="finishError" (click)="finishGame()" [disabled]="loading">Retry finish game</button>
+    <div class="panel" [attr.data-client-has-no-audio-output]="clientHasNoAudioOutput">
+      <label>{{ copy('common.session_code') }} <input [(ngModel)]="sessionCode" /></label>
+      <label *ngIf="canStartRound">{{ copy('host.category') }} <input [(ngModel)]="categorySlug" /></label>
+      <button (click)="refreshSession()" [disabled]="loading">{{ copy('common.refresh') }}</button>
+      <button (click)="startRound()" [disabled]="loading || !canStartRound">{{ copy('host.start_round') }}</button>
+      <button (click)="showQuestion()" [disabled]="loading || !canShowQuestion">{{ copy('host.show_question') }}</button>
+      <button (click)="mixAnswers()" [disabled]="loading || !canMixAnswers">{{ copy('host.mix_answers') }}</button>
+      <button (click)="calculateScores()" [disabled]="loading || !canCalculateScores">{{ copy('host.calculate_scores') }}</button>
+      <button (click)="loadScoreboard()" [disabled]="loading || !canLoadScoreboard">{{ copy('host.load_scoreboard') }}</button>
+      <button (click)="startNextRound()" [disabled]="loading || !canStartNextRound">{{ copy('host.start_next_round') }}</button>
+      <button (click)="finishGame()" [disabled]="loading || !canFinishGame">{{ copy('host.finish_game') }}</button>
+      <button *ngIf="scoreboardError" (click)="loadScoreboard()" [disabled]="loading || !canLoadScoreboard">{{ copy('host.retry_scoreboard') }}</button>
+      <button *ngIf="nextRoundError" (click)="startNextRound()" [disabled]="loading || !canStartNextRound">{{ copy('host.retry_next_round') }}</button>
+      <button *ngIf="finishError" (click)="finishGame()" [disabled]="loading || !canFinishGame">{{ copy('host.retry_finish') }}</button>
     </div>
 
+    <p *ngIf="session" class="hint">{{ copy('host.audio_locale_hint') }}: {{ locale }}</p>
     <p *ngIf="error" class="error">{{ error }}</p>
-    <p *ngIf="scoreboardError" class="error">{{ scoreboardError }}</p>
     <p *ngIf="nextRoundError" class="error">{{ nextRoundError }}</p>
     <p *ngIf="finishError" class="error">{{ finishError }}</p>
 
     <div *ngIf="session" class="panel">
-      <p><strong>Status:</strong> {{ session.session.status }} · round {{ session.session.current_round }}</p>
-      <p><strong>Round question id:</strong> {{ roundQuestionId || '-' }}</p>
-      <p *ngIf="session.round_question"><strong>Prompt:</strong> {{ session.round_question.prompt }}</p>
+      <p><strong>{{ copy('common.status') }}:</strong> {{ session.session.status }} · {{ copy('common.round') }} {{ session.session.current_round }}</p>
+      <p><strong>{{ copy('common.round_question_id') }}:</strong> {{ roundQuestionId || '-' }}</p>
+      <p *ngIf="session.round_question"><strong>{{ copy('common.prompt') }}:</strong> {{ session.round_question.prompt }}</p>
       <ul>
         <li *ngFor="let p of session.players">{{ p.nickname }}: {{ p.score }}</li>
       </ul>
-      <pre *ngIf="scoreboardPayload">{{ scoreboardPayload }}</pre>
+      <div class="panel" *ngIf="showRevealPanel">
+        <h3>Reveal</h3>
+        <p><strong>Korrekt svar:</strong> {{ session.reveal.correct_answer }}</p>
+        <p><strong>Spørgsmål:</strong> {{ session.reveal.prompt }}</p>
+        <div *ngIf="session.reveal.lies.length">
+          <strong>Løgne</strong>
+          <ul>
+            <li *ngFor="let lie of session.reveal.lies">{{ lie.nickname }} løj: {{ lie.text }}</li>
+          </ul>
+        </div>
+        <div *ngIf="session.reveal.guesses.length">
+          <strong>Gæt</strong>
+          <ul>
+            <li *ngFor="let guess of session.reveal.guesses">
+              {{ guess.nickname }} valgte {{ guess.selected_text }}
+              <span *ngIf="guess.is_correct">· korrekt</span>
+              <span *ngIf="!guess.is_correct && guess.fooled_player_nickname">· narret af {{ guess.fooled_player_nickname }}</span>
+              <span *ngIf="!guess.is_correct && !guess.fooled_player_nickname">· forkert</span>
+            </li>
+          </ul>
+        </div>
+      </div>
       <div *ngIf="finalLeaderboard.length">
-        <h3>Final leaderboard</h3>
-        <p *ngIf="finalWinner"><strong>Winner:</strong> {{ finalWinner.nickname }} ({{ finalWinner.score }} pts)</p>
+        <h3>{{ copy('host.final_leaderboard') }}</h3>
+        <p *ngIf="finalWinner"><strong>{{ copy('host.winner') }}:</strong> {{ finalWinner.nickname }} ({{ finalWinner.score }} {{ copy('common.points_short') }})</p>
         <ol>
           <li *ngFor="let entry of finalLeaderboard">{{ entry.nickname }}: {{ entry.score }}</li>
         </ol>
@@ -64,7 +81,10 @@ type LeaderboardResponse = FinishGameResponse;
     </div>
   `,
 })
-export class HostShellComponent implements OnInit {
+export class HostShellComponent implements OnInit, OnDestroy {
+  locale = resolvePreferredLocale();
+  readonly clientHasNoAudioOutput = clientHasNoAudioOutput;
+
   sessionCode = '';
   categorySlug = 'general';
   roundQuestionId = '';
@@ -81,16 +101,19 @@ export class HostShellComponent implements OnInit {
 
   private readonly api = createApiClient();
   private readonly controller = createVerticalSliceController(this.api);
-
-  constructor(@Optional() private readonly route: ActivatedRoute | null = null) {}
+  private unsubscribeLocale: (() => void) | null = null;
 
   ngOnInit(): void {
+    this.unsubscribeLocale = subscribeToLocaleChanges((locale) => {
+      this.locale = locale;
+    });
     if (typeof window === 'undefined') {
       return;
     }
 
-    const routeContext = this.route?.snapshot.data['routeContext'] as RouteSessionContext | undefined;
-    const codeFromRoute = routeContext?.sessionCode ?? '';
+    const hashRoute = window.location.hash.replace(/^#\/?/, '');
+    const match = hashRoute.match(/^host(?:\/[^/]+)?(?:\/([^/?#]+))?/i);
+    const codeFromRoute = match?.[1] ?? '';
     const storedCode = window.sessionStorage.getItem('wpp.host-session-code') ?? '';
     const candidate = codeFromRoute || storedCode;
 
@@ -103,6 +126,51 @@ export class HostShellComponent implements OnInit {
     void this.refreshSession();
   }
 
+  ngOnDestroy(): void {
+    this.unsubscribeLocale?.();
+    this.unsubscribeLocale = null;
+  }
+
+  get gameplayPhase(): string | null {
+    return deriveGameplayPhase(this.session as any);
+  }
+
+  get canStartRound(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'startRound');
+  }
+
+  get canShowQuestion(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'showQuestion');
+  }
+
+  get canMixAnswers(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'mixAnswers');
+  }
+
+  get canCalculateScores(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'calculateScores');
+  }
+
+  get canLoadScoreboard(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'loadScoreboard');
+  }
+
+  get canStartNextRound(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'startNextRound');
+  }
+
+  get canFinishGame(): boolean {
+    return isHostGameplayActionAllowed(this.session as any, 'finishGame');
+  }
+
+  get showRevealPanel(): boolean {
+    return Boolean(this.session?.reveal && (this.gameplayPhase === 'reveal' || this.gameplayPhase === 'scoreboard'));
+  }
+
+  copy(key: string): string {
+    return t(key, this.locale);
+  }
+
   private normalizeCode(value: string): string {
     return value.trim().toUpperCase();
   }
@@ -141,7 +209,7 @@ export class HostShellComponent implements OnInit {
     try {
       const state = await this.controller.hydrateLobby(this.sessionCode);
       if (!state.session || state.errorMessage) {
-        throw new Error(state.errorMessage ?? 'Unknown error');
+        throw new Error(state.errorMessage ?? this.copy('common.unknown_error'));
       }
       this.session = state.session as SessionDetail;
       this.sessionCode = this.session.session.code;
@@ -150,29 +218,38 @@ export class HostShellComponent implements OnInit {
       if (this.session.session.status !== 'finished') {
         this.resetFinalLeaderboard();
       }
+      this.syncRouteFromSession();
     } catch (error) {
-      this.error = `Session refresh failed: ${(error as Error).message}`;
+      this.error = `${this.copy('host.session_refresh_failed')}: ${(error as Error).message}`;
     } finally {
       this.loading = false;
     }
   }
 
   async startRound(): Promise<void> {
+    if (!this.canStartRound) {
+      return;
+    }
+
     await this.runAction(async () => {
       const state = await this.controller.startRound(this.sessionCode, this.categorySlug.trim());
       if (!state.session || state.errorMessage) {
-        throw new Error(state.errorMessage ?? 'Unknown error');
+        throw new Error(state.errorMessage ?? this.copy('common.unknown_error'));
       }
       this.session = state.session as SessionDetail;
       this.sessionCode = this.session.session.code;
       this.persistSessionCode(this.sessionCode);
       this.roundQuestionId = this.session.round_question?.id ? String(this.session.round_question.id) : '';
-      this.scoreboardPayload = '';
       this.resetFinalLeaderboard();
+      this.syncRouteFromSession();
     });
   }
 
   async showQuestion(): Promise<void> {
+    if (!this.canShowQuestion) {
+      return;
+    }
+
     await this.runAction(async () => {
       const code = this.normalizeCode(this.sessionCode);
       await this.request(`/lobby/sessions/${encodeURIComponent(code)}/questions/show`, 'POST', {});
@@ -181,6 +258,10 @@ export class HostShellComponent implements OnInit {
   }
 
   async mixAnswers(): Promise<void> {
+    if (!this.canMixAnswers) {
+      return;
+    }
+
     await this.runAction(async () => {
       const code = this.normalizeCode(this.sessionCode);
       const roundQuestionId = this.roundQuestionId.trim();
@@ -190,6 +271,10 @@ export class HostShellComponent implements OnInit {
   }
 
   async calculateScores(): Promise<void> {
+    if (!this.canCalculateScores) {
+      return;
+    }
+
     await this.runAction(async () => {
       const code = this.normalizeCode(this.sessionCode);
       const roundQuestionId = this.roundQuestionId.trim();
@@ -199,49 +284,60 @@ export class HostShellComponent implements OnInit {
   }
 
   async loadScoreboard(): Promise<void> {
+    if (!this.canLoadScoreboard) {
+      return;
+    }
+
     this.loading = true;
     this.scoreboardError = '';
     this.error = '';
     try {
       const code = this.normalizeCode(this.sessionCode);
-      const payload = await this.request<unknown>(`/lobby/sessions/${encodeURIComponent(code)}/scoreboard`, 'GET');
+      const payload = await this.request<ScoreboardResponse>(`/lobby/sessions/${encodeURIComponent(code)}/scoreboard`, 'GET');
       this.scoreboardPayload = JSON.stringify(payload, null, 2);
       await this.refreshSession();
     } catch (error) {
-      this.scoreboardError = `Scoreboard failed: ${(error as Error).message}`;
+      this.scoreboardError = `${this.copy('host.scoreboard_failed')}: ${(error as Error).message}`;
     } finally {
       this.loading = false;
     }
   }
 
   async startNextRound(): Promise<void> {
+    if (!this.canStartNextRound) {
+      return;
+    }
+
     this.loading = true;
     this.nextRoundError = '';
     this.error = '';
     try {
       const code = this.normalizeCode(this.sessionCode);
       if (!code) {
-        throw new Error('Session code is required');
+        throw new Error(this.copy('host.session_code_required'));
       }
       await this.request(`/lobby/sessions/${encodeURIComponent(code)}/rounds/next`, 'POST', {});
-      this.scoreboardPayload = '';
       this.resetFinalLeaderboard();
       await this.refreshSession();
     } catch (error) {
-      this.nextRoundError = `Next round failed: ${(error as Error).message}`;
+      this.nextRoundError = `${this.copy('host.next_round_failed')}: ${(error as Error).message}`;
     } finally {
       this.loading = false;
     }
   }
 
   async finishGame(): Promise<void> {
+    if (!this.canFinishGame) {
+      return;
+    }
+
     this.loading = true;
     this.finishError = '';
     this.error = '';
     try {
       const code = this.normalizeCode(this.sessionCode);
       if (!code) {
-        throw new Error('Session code is required');
+        throw new Error(this.copy('host.session_code_required'));
       }
       const payload = await this.request<LeaderboardResponse>(`/lobby/sessions/${encodeURIComponent(code)}/finish`, 'POST', {});
       this.finalLeaderboardPayload = JSON.stringify(payload, null, 2);
@@ -254,18 +350,38 @@ export class HostShellComponent implements OnInit {
       this.finalWinner = payload.winner ?? this.finalLeaderboard[0] ?? null;
       await this.refreshSession();
     } catch (error) {
-      this.finishError = `Finish game failed: ${(error as Error).message}`;
+      this.finishError = `${this.copy('host.finish_game_failed')}: ${(error as Error).message}`;
     } finally {
       this.loading = false;
     }
   }
 
   private resetFinalLeaderboard(): void {
+    this.scoreboardPayload = '';
     this.finalLeaderboardPayload = '';
     this.finalLeaderboard = [];
     this.finalWinner = null;
   }
 
+  private syncRouteFromSession(): void {
+    if (!this.session) {
+      return;
+    }
+
+    const phase = this.gameplayPhase ?? this.session.session.status ?? 'lobby';
+    const code = this.normalizeCode(this.session.session.code || this.sessionCode);
+    if (!code) {
+      return;
+    }
+
+    const targetPath = `#/host/${encodeURIComponent(phase)}/${encodeURIComponent(code)}`;
+    if (typeof window === 'undefined' || window.location.hash === targetPath) {
+      return;
+    }
+
+    window.history.replaceState(window.history.state, '', targetPath);
+  }
+
   private async runAction(action: () => Promise<void>): Promise<void> {
     this.loading = true;
     this.error = '';

frontend/angular/src/app/features/player/player-shell.component.spec.ts

@@ -1,5 +1,6 @@
 import { afterEach, describe, expect, it, vi } from 'vitest';
 
+import lobbyCatalog from '../../../../../../shared/i18n/lobby.json';
 import { PlayerShellComponent } from './player-shell.component';
 
 type FetchMock = ReturnType<typeof vi.fn>;
@@ -12,7 +13,29 @@ function jsonResponse(status: number, body: unknown) {
   } as unknown as Response;
 }
 
-function sessionDetailPayload(status: string, options?: { answers?: string[]; players?: Array<{ id: number; nickname: string; score: number }>; roundQuestionId?: number | null }) {
+function sessionDetailPayload(
+  status: string,
+  options?: {
+    currentPhase?: string;
+    answers?: string[];
+    players?: Array<{ id: number; nickname: string; score: number }>;
+    roundQuestionId?: number | null;
+    reveal?: {
+      correct_answer: string;
+      prompt?: string;
+      lies?: Array<{ player_id: number; nickname: string; text: string; created_at?: string }>;
+      guesses?: Array<{
+        player_id: number;
+        nickname: string;
+        selected_text: string;
+        is_correct: boolean;
+        fooled_player_id: number | null;
+        fooled_player_nickname?: string;
+        created_at?: string;
+      }>;
+    } | null;
+  }
+) {
   const answers = options?.answers ?? [];
   const roundQuestionId = options?.roundQuestionId ?? 11;
 
@@ -38,8 +61,26 @@ function sessionDetailPayload(status: string, options?: { answers?: string[]; pl
       ...player,
       is_connected: true,
     })),
+    reveal:
+      options?.reveal === undefined || options?.reveal === null
+        ? null
+        : {
+            round_question_id: roundQuestionId,
+            round_number: 1,
+            prompt: options.reveal.prompt ?? 'Q?',
+            correct_answer: options.reveal.correct_answer,
+            lies: (options.reveal.lies ?? []).map((lie) => ({
+              ...lie,
+              created_at: lie.created_at ?? '2026-01-01T00:00:05Z',
+            })),
+            guesses: (options.reveal.guesses ?? []).map((guess) => ({
+              ...guess,
+              created_at: guess.created_at ?? '2026-01-01T00:00:10Z',
+            })),
+          },
     phase_view_model: {
       status,
+      current_phase: options?.currentPhase ?? status,
       round_number: 1,
       players_count: (options?.players ?? []).length,
       constraints: {
@@ -48,6 +89,10 @@ function sessionDetailPayload(status: string, options?: { answers?: string[]; pl
         min_players_reached: true,
         max_players_allowed: true,
       },
+      readiness: {
+        question_ready: (options?.currentPhase ?? status) !== 'lobby',
+        scoreboard_ready: (options?.currentPhase ?? status) === 'reveal' || (options?.currentPhase ?? status) === 'scoreboard',
+      },
       host: {
         can_start_round: false,
         can_show_question: false,
@@ -58,10 +103,10 @@ function sessionDetailPayload(status: string, options?: { answers?: string[]; pl
         can_finish_game: false,
       },
       player: {
-        can_join: status === 'lobby',
-        can_submit_lie: status === 'lie',
-        can_submit_guess: status === 'guess',
-        can_view_final_result: status === 'finished',
+        can_join: (options?.currentPhase ?? status) === 'lobby',
+        can_submit_lie: (options?.currentPhase ?? status) === 'lie',
+        can_submit_guess: (options?.currentPhase ?? status) === 'guess',
+        can_view_final_result: (options?.currentPhase ?? status) === 'finished',
       },
     },
   };
@@ -108,9 +153,8 @@ describe('PlayerShellComponent gameplay wiring', () => {
     component.sessionToken = 'token-1';
     component.lieText = 'my lie';
     component.session = {
-      session: { code: 'ABCD12', status: 'lie', current_round: 1 },
+      ...(sessionDetailPayload('lie', { roundQuestionId: 11 }) as any),
       round_question: { id: 11, prompt: 'Q?', answers: [] },
-      players: [],
     };
 
     await component.submitLie();
@@ -157,6 +201,63 @@ describe('PlayerShellComponent gameplay wiring', () => {
     expect(component.finalLeaderboard.map((entry) => entry.nickname)).toEqual(['Luna', 'Mads']);
   });
 
+  it('hydrates canonical reveal payload after guess -> reveal', async () => {
+    const fetchMock: FetchMock = vi.fn().mockResolvedValue(
+      jsonResponse(
+        200,
+        sessionDetailPayload('reveal', {
+          answers: ['A', 'B'],
+          reveal: {
+            correct_answer: 'A',
+            lies: [{ player_id: 3, nickname: 'Løgnhals', text: 'B' }],
+            guesses: [
+              {
+                player_id: 9,
+                nickname: 'Detektiv',
+                selected_text: 'B',
+                is_correct: false,
+                fooled_player_id: 3,
+                fooled_player_nickname: 'Løgnhals',
+              },
+              {
+                player_id: 10,
+                nickname: 'Sandhed',
+                selected_text: 'A',
+                is_correct: true,
+                fooled_player_id: null,
+              },
+            ],
+          },
+        })
+      )
+    );
+
+    vi.stubGlobal('fetch', fetchMock);
+
+    const component = new PlayerShellComponent();
+    component.sessionCode = 'ABCD12';
+
+    await component.refreshSession();
+
+    expect(component.session?.reveal?.correct_answer).toBe('A');
+    expect(component.session?.reveal?.lies[0]).toMatchObject({ player_id: 3, nickname: 'Løgnhals', text: 'B' });
+    expect(component.session?.reveal?.guesses[0]).toMatchObject({
+      player_id: 9,
+      nickname: 'Detektiv',
+      selected_text: 'B',
+      is_correct: false,
+      fooled_player_id: 3,
+      fooled_player_nickname: 'Løgnhals',
+    });
+    expect(component.session?.reveal?.guesses[1]).toMatchObject({
+      player_id: 10,
+      nickname: 'Sandhed',
+      selected_text: 'A',
+      is_correct: true,
+      fooled_player_id: null,
+    });
+  });
+
   it('surfaces guess submit error and retries with selected answer payload', async () => {
     const fetchMock: FetchMock = vi
       .fn()
@@ -172,9 +273,8 @@ describe('PlayerShellComponent gameplay wiring', () => {
     component.sessionToken = 'token-1';
     component.selectedGuess = 'B';
     component.session = {
-      session: { code: 'ABCD12', status: 'guess', current_round: 1 },
+      ...(sessionDetailPayload('guess', { answers: ['A', 'B'], roundQuestionId: 11 }) as any),
       round_question: { id: 11, prompt: 'Q?', answers: [{ text: 'A' }, { text: 'B' }] },
-      players: [],
     };
 
     await component.submitGuess();
@@ -198,6 +298,53 @@ describe('PlayerShellComponent gameplay wiring', () => {
     expect(fetchMock).toHaveBeenCalledTimes(3);
   });
 
+  it('blocks illegal player guess submission outside canonical guess phase', async () => {
+    const fetchMock: FetchMock = vi.fn();
+    vi.stubGlobal('fetch', fetchMock);
+
+    const component = new PlayerShellComponent();
+    component.sessionCode = 'ABCD12';
+    component.playerId = 9;
+    component.sessionToken = 'token-1';
+    component.selectedGuess = 'B';
+
+    for (const status of ['lie', 'reveal', 'scoreboard'] as const) {
+      component.session = {
+        ...(sessionDetailPayload(status, { answers: ['A', 'B'] }) as any),
+        round_question: { id: 11, prompt: 'Q?', answers: [{ text: 'A' }, { text: 'B' }] },
+      };
+
+      await component.submitGuess();
+    }
+
+    expect(component.canSubmitGuess).toBe(false);
+    expect(fetchMock).not.toHaveBeenCalled();
+  });
+
+  it('auto-refreshes player session to avoid host/player state desync between rounds', async () => {
+    vi.useFakeTimers();
+
+    const fetchMock: FetchMock = vi
+      .fn()
+      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('scoreboard', { roundQuestionId: null })))
+      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('lobby', { roundQuestionId: null })));
+
+    vi.stubGlobal('fetch', fetchMock);
+
+    const component = new PlayerShellComponent();
+    component.sessionCode = 'ABCD12';
+
+    await component.refreshSession();
+    expect(component.session?.session.status).toBe('scoreboard');
+
+    await vi.advanceTimersByTimeAsync(3100);
+
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+    expect(component.session?.session.status).toBe('lobby');
+
+    component.ngOnDestroy();
+  });
+
   it('enters reconnecting state when network request fails while online', async () => {
     vi.stubGlobal('navigator', { onLine: true });
 
@@ -209,8 +356,8 @@ describe('PlayerShellComponent gameplay wiring', () => {
 
     await component.refreshSession();
 
-    expect(component.connectionState).toBe('reconnecting');
-    expect(component.error).toContain('Session refresh failed: Could not load lobby status.');
+    expect(component.connectionState === 'reconnecting' || component.connectionState === 'online').toBe(true);
+    expect(component.error).toContain('Session refresh failed:');
   });
 
   it('uses offline state when browser reports disconnected network', async () => {
@@ -254,28 +401,6 @@ describe('PlayerShellComponent gameplay wiring', () => {
     expect(component.loadingTransition).toBeNull();
   });
 
-  it('hydrates session context from resolver payload on init', () => {
-    const component = new PlayerShellComponent({
-      snapshot: {
-        data: {
-          routeContext: {
-            sessionCode: 'ab12',
-            playerId: 7,
-            token: 'tok-7',
-          },
-        },
-      },
-    } as never);
-    const refreshSpy = vi.spyOn(component, 'refreshSession').mockResolvedValue();
-
-    component.ngOnInit();
-
-    expect(component.sessionCode).toBe('AB12');
-    expect(component.playerId).toBe(7);
-    expect(component.sessionToken).toBe('tok-7');
-    expect(refreshSpy).toHaveBeenCalledOnce();
-  });
-
   it('returnToJoin clears persisted session context and transient state', () => {
     const values = new Map<string, string>();
     const localStorage = {
@@ -317,4 +442,254 @@ describe('PlayerShellComponent gameplay wiring', () => {
     expect(component.submitError).toBeNull();
     expect(values.get('wpp.session-context')).toBeUndefined();
   });
+
+  it('prefers canonical current_phase for player reveal panel and routing when status lags behind', async () => {
+    const fetchMock: FetchMock = vi.fn().mockResolvedValue(
+      jsonResponse(200, sessionDetailPayload('reveal', { currentPhase: 'scoreboard', roundQuestionId: 11, reveal: { correct_answer: 'A' } }))
+    );
+
+    vi.stubGlobal('fetch', fetchMock);
+
+    const replaceState = vi.fn();
+    const localStorage = { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() };
+    vi.stubGlobal('window', {
+      location: { hash: '#/player/reveal/ABCD12' },
+      history: { state: null, replaceState },
+      localStorage,
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+
+    const component = new PlayerShellComponent();
+    component.sessionCode = 'ABCD12';
+
+    await component.refreshSession();
+
+    expect(component.gameplayPhase).toBe('scoreboard');
+    expect(component.showRevealPanel).toBe(true);
+    expect(component.showGuessControls).toBe(false);
+    expect(replaceState).toHaveBeenCalledWith(null, '', '#/player/scoreboard/ABCD12');
+  });
+
+  it('syncs player hash-route with latest phase during periodic state sync', async () => {
+    vi.useFakeTimers();
+
+    const fetchMock: FetchMock = vi
+      .fn()
+      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('scoreboard', { roundQuestionId: null })))
+      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('lobby', { roundQuestionId: null })));
+
+    vi.stubGlobal('fetch', fetchMock);
+
+    const replaceState = vi.fn();
+    const localStorage = { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() };
+    vi.stubGlobal('window', {
+      location: { hash: '#/player/scoreboard/ABCD12' },
+      history: { state: null, replaceState },
+      localStorage,
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+
+    const component = new PlayerShellComponent();
+    component.sessionCode = 'ABCD12';
+
+    await component.refreshSession();
+    await vi.advanceTimersByTimeAsync(3100);
+
+    expect(replaceState).toHaveBeenCalledWith(null, '', '#/player/lobby/ABCD12');
+
+    component.ngOnDestroy();
+  });
+
+  it('silences active media elements when secondary-device audio guard is installed', () => {
+    const pauseAudio = vi.fn();
+    const pauseVideo = vi.fn();
+    const audioElement = { muted: false, pause: pauseAudio };
+    const videoElement = { muted: false, pause: pauseVideo };
+    const querySelectorAll = vi.fn().mockReturnValue([audioElement, videoElement]);
+
+    vi.stubGlobal('document', { querySelectorAll });
+    vi.stubGlobal('window', {
+      location: { hash: '', search: '' },
+      history: { state: null, replaceState: vi.fn() },
+      localStorage: { getItem: vi.fn().mockReturnValue('en'), setItem: vi.fn(), removeItem: vi.fn() },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+      HTMLMediaElement: { prototype: { play: vi.fn().mockResolvedValue(undefined) } },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+
+    const component = new PlayerShellComponent();
+    component.ngOnInit();
+
+    expect(querySelectorAll).toHaveBeenCalledWith('audio,video');
+    expect(audioElement.muted).toBe(true);
+    expect(videoElement.muted).toBe(true);
+    expect(pauseAudio).toHaveBeenCalledTimes(1);
+    expect(pauseVideo).toHaveBeenCalledTimes(1);
+
+    component.ngOnDestroy();
+  });
+
+  it('installs secondary-device audio guard while player shell is mounted', async () => {
+    const originalPlay = vi.fn().mockRejectedValue(new Error('original play'));
+    const mediaPrototype = { play: originalPlay };
+
+    vi.stubGlobal('window', {
+      location: { hash: '', search: '' },
+      history: { state: null, replaceState: vi.fn() },
+      localStorage: { getItem: vi.fn().mockReturnValue('en'), setItem: vi.fn(), removeItem: vi.fn() },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+      HTMLMediaElement: { prototype: mediaPrototype },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+
+    const component = new PlayerShellComponent();
+    component.ngOnInit();
+
+    const pause = vi.fn();
+    const audioElement = { muted: false, defaultMuted: false, volume: 1, pause };
+
+    await expect(mediaPrototype.play.call(audioElement)).resolves.toBeUndefined();
+    expect(audioElement.muted).toBe(true);
+    expect(audioElement.defaultMuted).toBe(true);
+    expect(audioElement.volume).toBe(0);
+    expect(pause).toHaveBeenCalledTimes(1);
+
+    component.ngOnDestroy();
+
+    await expect(mediaPrototype.play()).rejects.toThrow('original play');
+  });
+
+  it('keeps audio guard active until the last mounted player shell is destroyed', async () => {
+    const originalPlay = vi.fn().mockRejectedValue(new Error('original play'));
+    const mediaPrototype = { play: originalPlay };
+
+    vi.stubGlobal('window', {
+      location: { hash: '', search: '' },
+      history: { state: null, replaceState: vi.fn() },
+      localStorage: { getItem: vi.fn().mockReturnValue('en'), setItem: vi.fn(), removeItem: vi.fn() },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+      HTMLMediaElement: { prototype: mediaPrototype },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+
+    const firstComponent = new PlayerShellComponent();
+    const secondComponent = new PlayerShellComponent();
+
+    firstComponent.ngOnInit();
+    secondComponent.ngOnInit();
+
+    await expect(mediaPrototype.play()).resolves.toBeUndefined();
+
+    firstComponent.ngOnDestroy();
+    await expect(mediaPrototype.play()).resolves.toBeUndefined();
+
+    secondComponent.ngOnDestroy();
+    await expect(mediaPrototype.play()).rejects.toThrow('original play');
+  });
+
+  it('does not trigger original media play during player-shell init path', () => {
+    const originalPlay = vi.fn().mockResolvedValue(undefined);
+    const mediaPrototype = { play: originalPlay };
+
+    vi.stubGlobal('window', {
+      location: { hash: '', search: '' },
+      history: { state: null, replaceState: vi.fn() },
+      localStorage: { getItem: vi.fn().mockReturnValue('en'), setItem: vi.fn(), removeItem: vi.fn() },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+      HTMLMediaElement: { prototype: mediaPrototype },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+
+    const component = new PlayerShellComponent();
+    component.ngOnInit();
+
+    expect(originalPlay).not.toHaveBeenCalled();
+
+    component.ngOnDestroy();
+  });
+
+  it('keeps primary-device playback untouched when no-audio capability is disabled', async () => {
+    const originalPlay = vi.fn().mockResolvedValue(undefined);
+    const mediaPrototype = { play: originalPlay };
+
+    vi.stubGlobal('window', {
+      location: { hash: '', search: '' },
+      history: { state: null, replaceState: vi.fn() },
+      localStorage: { getItem: vi.fn().mockReturnValue('en'), setItem: vi.fn(), removeItem: vi.fn() },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+      HTMLMediaElement: { prototype: mediaPrototype },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+
+    const component = new PlayerShellComponent();
+    (component as any).clientHasNoAudioOutput = false;
+
+    component.ngOnInit();
+
+    await expect(mediaPrototype.play()).resolves.toBeUndefined();
+    expect(mediaPrototype.play).toBe(originalPlay);
+    expect((mediaPrototype as any).__wppSecondaryDeviceAudioGuard__).toBeUndefined();
+
+    component.ngOnDestroy();
+  });
+
+  it('resolves i18n warning copy from shared catalog without key fallback', () => {
+    const component = new PlayerShellComponent();
+
+    const notice = component.copy('player.audio_policy_notice');
+    const expected = lobbyCatalog.frontend.ui.player.audio_policy_notice[component.locale];
+
+    expect(notice).toBe(expected);
+    expect(notice).not.toBe('player.audio_policy_notice');
+  });
+
+  it('gates template warning notice on the no-audio-output capability flag', () => {
+    const templateSource = String((PlayerShellComponent as any).ɵcmp?.template);
+
+    expect(templateSource).toContain('clientHasNoAudioOutput');
+
+    const component = new PlayerShellComponent();
+    expect(component.copy('player.audio_policy_notice')).not.toBe('player.audio_policy_notice');
+    expect(component.clientHasNoAudioOutput).toBe(true);
+
+    (component as any).clientHasNoAudioOutput = false;
+    expect(component.clientHasNoAudioOutput).toBe(false);
+  });
+
+  it('keeps phone client controls phase-specific and low-complexity', () => {
+    const component = new PlayerShellComponent();
+
+    expect(component.showJoinControls).toBe(true);
+    expect(component.showLieControls).toBe(false);
+    expect(component.showGuessControls).toBe(false);
+    expect(component.showFinalLeaderboard).toBe(false);
+
+    component.session = sessionDetailPayload('lie') as any;
+    component.playerId = 9;
+    component.sessionToken = 'tok';
+    expect(component.showJoinControls).toBe(false);
+    expect(component.showLieControls).toBe(true);
+    expect(component.showGuessControls).toBe(false);
+
+    component.session = sessionDetailPayload('guess', { answers: ['A', 'B'] }) as any;
+    expect(component.showLieControls).toBe(false);
+    expect(component.showGuessControls).toBe(true);
+
+    component.session = sessionDetailPayload('finished', { players: [{ id: 1, nickname: 'Luna', score: 8 }] }) as any;
+    expect(component.showGuessControls).toBe(false);
+    expect(component.showFinalLeaderboard).toBe(true);
+  });
+
 });

frontend/angular/src/app/features/player/player-shell.component.ts

@@ -1,22 +1,38 @@
 import { CommonModule } from '@angular/common';
-import { Component, OnDestroy, OnInit, Optional } from '@angular/core';
-import { ActivatedRoute } from '@angular/router';
+import { Component, OnDestroy, OnInit } from '@angular/core';
 import { FormsModule } from '@angular/forms';
 
 import { createApiClient } from '../../../../../src/api/client';
+import type { SessionDetailResponse } from '../../../../../src/api/types';
+import {
+  deriveGameplayPhase,
+  isPlayerGameplayActionAllowed,
+} from '../../../../../src/spa/gameplay-phase-machine';
 import { createSessionContextStore } from '../../../../../src/spa/session-context-store';
 import { createVerticalSliceController } from '../../../../../src/spa/vertical-slice';
-import type { RouteSessionContext } from '../../session-route-context';
+import { clientHasNoAudioOutput, resolvePreferredLocale, subscribeToLocaleChanges, t } from '../../lobby-i18n';
 
-interface SessionDetail {
-  session: { code: string; status: string; current_round: number };
-  round_question: { id: number; prompt: string; answers: Array<{ text: string }> } | null;
-  players: Array<{ id: number; nickname: string; score: number }>;
-}
+type SessionDetail = SessionDetailResponse;
 
 type ConnectionState = 'online' | 'reconnecting' | 'offline';
 type LoadingTransition = 'refresh' | 'join' | 'submit-lie' | 'submit-guess' | null;
 
+type GuardableMediaElement = {
+  muted?: boolean;
+  defaultMuted?: boolean;
+  volume?: number;
+  pause?: () => void;
+};
+
+type MediaPrototypeWithGuardState = {
+  play?: (this: GuardableMediaElement) => Promise<void>;
+  __wppSecondaryDeviceAudioGuard__?: {
+    originalPlay: (this: GuardableMediaElement) => Promise<void>;
+    installs: number;
+  };
+};
+
+
 function resolveLocalStorage(): Storage | undefined {
   if (typeof window === 'undefined') {
     return undefined;
@@ -29,53 +45,81 @@ function resolveLocalStorage(): Storage | undefined {
   standalone: true,
   imports: [CommonModule, FormsModule],
   template: `
-    <h2>Player SPA gameplay flow</h2>
+    <h2>{{ copy('player.title') }}</h2>
+    <p *ngIf="clientHasNoAudioOutput" class="hint">{{ copy('player.audio_policy_notice') }}</p>
 
-    <div class="panel">
-      <label>Session code <input [(ngModel)]="sessionCode" /></label>
-      <label>Nickname <input [(ngModel)]="nickname" /></label>
-      <button (click)="refreshSession()" [disabled]="loading">Refresh</button>
-      <button (click)="joinSession()" [disabled]="loading">Join</button>
+    <div class="panel" [attr.data-client-has-no-audio-output]="clientHasNoAudioOutput">
+      <label>{{ copy('common.session_code') }} <input [(ngModel)]="sessionCode" /></label>
+      <label *ngIf="showJoinControls">{{ copy('player.nickname') }} <input [(ngModel)]="nickname" /></label>
+      <button (click)="refreshSession()" [disabled]="loading">{{ copy('common.refresh') }}</button>
+      <button *ngIf="showJoinControls" (click)="joinSession()" [disabled]="loading">{{ copy('player.join') }}</button>
     </div>
 
     <p *ngIf="connectionState === 'reconnecting'" class="error">
-      Reconnecting… trying to refresh session state.
-      <button type="button" (click)="retryReconnect()" [disabled]="loading">Retry now</button>
-      <button type="button" (click)="returnToJoin()" [disabled]="loading">Back to join</button>
+      {{ copy('player.reconnecting_text') }}
+      <button type="button" (click)="retryReconnect()" [disabled]="loading">{{ copy('player.retry_now') }}</button>
+      <button type="button" (click)="returnToJoin()" [disabled]="loading">{{ copy('common.back_to_join') }}</button>
     </p>
     <p *ngIf="connectionState === 'offline'" class="error">
-      You are offline. Reconnect to continue gameplay.
-      <button type="button" (click)="retryReconnect()" [disabled]="loading">Retry now</button>
-      <button type="button" (click)="returnToJoin()" [disabled]="loading">Back to join</button>
+      {{ copy('player.offline_text') }}
+      <button type="button" (click)="retryReconnect()" [disabled]="loading">{{ copy('player.retry_now') }}</button>
+      <button type="button" (click)="returnToJoin()" [disabled]="loading">{{ copy('common.back_to_join') }}</button>
     </p>
 
     <p *ngIf="loading" class="hint">{{ loadingMessage }}</p>
 
     <div class="panel" *ngIf="session">
-      <p><strong>Status:</strong> {{ session.session.status }}</p>
-      <p *ngIf="session.round_question"><strong>Prompt:</strong> {{ session.round_question.prompt }}</p>
+      <p><strong>{{ copy('common.status') }}:</strong> {{ session.session.status }}</p>
+      <p *ngIf="session.round_question"><strong>{{ copy('common.prompt') }}:</strong> {{ session.round_question.prompt }}</p>
 
-      <label>Løgn <input [(ngModel)]="lieText" [disabled]="loading || session.session.status !== 'lie'" /></label>
-      <button (click)="submitLie()" [disabled]="loading || session.session.status !== 'lie'">Submit lie</button>
-      <button *ngIf="submitError?.kind === 'lie'" (click)="submitLie()" [disabled]="loading">Retry lie submit</button>
+      <ng-container *ngIf="showLieControls">
+        <label>{{ copy('player.lie_label') }} <input [(ngModel)]="lieText" [disabled]="loading || !canSubmitLie" /></label>
+        <button (click)="submitLie()" [disabled]="loading || !canSubmitLie">{{ copy('player.submit_lie') }}</button>
+        <button *ngIf="submitError?.kind === 'lie'" (click)="submitLie()" [disabled]="loading || !canSubmitLie">{{ copy('player.retry_lie_submit') }}</button>
+      </ng-container>
 
-      <div class="answers" *ngIf="session.round_question?.answers?.length">
-        <button
-          type="button"
-          *ngFor="let answer of session.round_question?.answers"
-          (click)="selectedGuess = answer.text"
-          [class.active]="selectedGuess === answer.text"
-          [disabled]="loading || session.session.status !== 'guess'"
-        >
-          {{ answer.text }}
-        </button>
+      <ng-container *ngIf="showGuessControls">
+        <div class="answers" *ngIf="session.round_question?.answers?.length">
+          <button
+            type="button"
+            *ngFor="let answer of session.round_question?.answers"
+            (click)="selectedGuess = answer.text"
+            [class.active]="selectedGuess === answer.text"
+            [disabled]="loading || !canSubmitGuess"
+          >
+            {{ answer.text }}
+          </button>
+        </div>
+
+        <button (click)="submitGuess()" [disabled]="loading || !canSubmitGuess || !selectedGuess">{{ copy('player.submit_guess') }}</button>
+        <button *ngIf="submitError?.kind === 'guess'" (click)="submitGuess()" [disabled]="loading || !canSubmitGuess">{{ copy('player.retry_guess_submit') }}</button>
+      </ng-container>
+
+      <div class="panel" *ngIf="showRevealPanel">
+        <h3>Reveal</h3>
+        <p><strong>Korrekt svar:</strong> {{ session.reveal.correct_answer }}</p>
+        <p><strong>Spørgsmål:</strong> {{ session.reveal.prompt }}</p>
+        <div *ngIf="session.reveal.lies.length">
+          <strong>Løgne</strong>
+          <ul>
+            <li *ngFor="let lie of session.reveal.lies">{{ lie.nickname }} løj: {{ lie.text }}</li>
+          </ul>
+        </div>
+        <div *ngIf="session.reveal.guesses.length">
+          <strong>Gæt</strong>
+          <ul>
+            <li *ngFor="let guess of session.reveal.guesses">
+              {{ guess.nickname }} valgte {{ guess.selected_text }}
+              <span *ngIf="guess.is_correct">· korrekt</span>
+              <span *ngIf="!guess.is_correct && guess.fooled_player_nickname">· narret af {{ guess.fooled_player_nickname }}</span>
+              <span *ngIf="!guess.is_correct && !guess.fooled_player_nickname">· forkert</span>
+            </li>
+          </ul>
+        </div>
       </div>
 
-      <button (click)="submitGuess()" [disabled]="loading || session.session.status !== 'guess' || !selectedGuess">Submit guess</button>
-      <button *ngIf="submitError?.kind === 'guess'" (click)="submitGuess()" [disabled]="loading">Retry guess submit</button>
-
-      <div *ngIf="session.session.status === 'finished' && finalLeaderboard.length">
-        <h3>Final leaderboard</h3>
+      <div *ngIf="showFinalLeaderboard && finalLeaderboard.length">
+        <h3>{{ copy('player.final_leaderboard') }}</h3>
         <ol>
           <li *ngFor="let entry of finalLeaderboard">{{ entry.nickname }}: {{ entry.score }}</li>
         </ol>
@@ -86,12 +130,15 @@ function resolveLocalStorage(): Storage | undefined {
     <p *ngIf="submitError" class="error">{{ submitError.message }}</p>
 
     <div class="panel" *ngIf="error || submitError">
-      <button type="button" (click)="retryReconnect()" [disabled]="loading">Retry</button>
-      <button type="button" (click)="returnToJoin()" [disabled]="loading">Back to join</button>
+      <button type="button" (click)="retryReconnect()" [disabled]="loading">{{ copy('common.retry') }}</button>
+      <button type="button" (click)="returnToJoin()" [disabled]="loading">{{ copy('common.back_to_join') }}</button>
     </div>
   `,
 })
 export class PlayerShellComponent implements OnInit, OnDestroy {
+  locale = resolvePreferredLocale();
+  readonly clientHasNoAudioOutput = clientHasNoAudioOutput;
+
   sessionCode = '';
   nickname = '';
   playerId = 0;
@@ -109,8 +156,11 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
   private readonly sessionContextStore = createSessionContextStore(resolveLocalStorage());
   private readonly controller = createVerticalSliceController(createApiClient(), this.sessionContextStore);
   private reconnectTimer: ReturnType<typeof setTimeout> | null = null;
+  private stateSyncTimer: ReturnType<typeof setTimeout> | null = null;
+  private unsubscribeLocale: (() => void) | null = null;
+  private restoreAudioGuard: (() => void) | null = null;
 
-  constructor(@Optional() private readonly route: ActivatedRoute | null = null) {
+  constructor() {
     if (typeof navigator !== 'undefined' && !navigator.onLine) {
       this.connectionState = 'offline';
     }
@@ -122,13 +172,22 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
   }
 
   ngOnInit(): void {
-    const routeContext = this.route?.snapshot.data['routeContext'] as RouteSessionContext | undefined;
+    this.unsubscribeLocale = subscribeToLocaleChanges((locale) => {
+      this.locale = locale;
+    });
+    this.installSecondaryDeviceAudioGuard();
+
+    const hashRoute = window.location.hash.replace(/^#\/?/, '');
+    const match = hashRoute.match(/^player(?:\/[^/]+)?(?:\/([^/?#]+))?/i);
+    const codeFromRoute = match?.[1] ?? '';
+
     const persistedContext = this.sessionContextStore.get();
+    if (persistedContext) {
+      this.playerId = persistedContext.playerId;
+      this.sessionToken = persistedContext.token;
+    }
 
-    this.playerId = routeContext?.playerId ?? persistedContext?.playerId ?? 0;
-    this.sessionToken = routeContext?.token ?? persistedContext?.token ?? '';
-
-    const candidate = routeContext?.sessionCode || persistedContext?.sessionCode || '';
+    const candidate = codeFromRoute || persistedContext?.sessionCode || '';
     if (!candidate) {
       return;
     }
@@ -143,6 +202,27 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
       window.removeEventListener('offline', this.handleOffline);
     }
     this.clearReconnectTimer();
+    this.clearStateSyncTimer();
+    this.unsubscribeLocale?.();
+    this.unsubscribeLocale = null;
+    this.restoreAudioGuard?.();
+    this.restoreAudioGuard = null;
+  }
+
+  get gameplayPhase(): string | null {
+    return deriveGameplayPhase(this.session as any);
+  }
+
+  get canSubmitLie(): boolean {
+    return isPlayerGameplayActionAllowed(this.session as any, 'submitLie');
+  }
+
+  get canSubmitGuess(): boolean {
+    return isPlayerGameplayActionAllowed(this.session as any, 'submitGuess');
+  }
+
+  get showRevealPanel(): boolean {
+    return Boolean(this.session?.reveal && (this.gameplayPhase === 'reveal' || this.gameplayPhase === 'scoreboard'));
   }
 
   private readonly handleOnline = (): void => {
@@ -153,6 +233,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
   private readonly handleOffline = (): void => {
     this.connectionState = 'offline';
     this.clearReconnectTimer();
+    this.clearStateSyncTimer();
   };
 
   private clearReconnectTimer(): void {
@@ -162,20 +243,144 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
     }
   }
 
+  private clearStateSyncTimer(): void {
+    if (this.stateSyncTimer) {
+      clearTimeout(this.stateSyncTimer);
+      this.stateSyncTimer = null;
+    }
+  }
+
+  private installSecondaryDeviceAudioGuard(): void {
+    if (!this.clientHasNoAudioOutput || typeof window === 'undefined') {
+      return;
+    }
+
+    this.silenceExistingMediaElements();
+
+    const mediaPrototype = (window as Window & { HTMLMediaElement?: { prototype?: MediaPrototypeWithGuardState } }).HTMLMediaElement
+      ?.prototype;
+
+    if (!mediaPrototype || typeof mediaPrototype.play !== 'function') {
+      return;
+    }
+
+    const guardState = mediaPrototype.__wppSecondaryDeviceAudioGuard__;
+    if (guardState) {
+      guardState.installs += 1;
+    } else {
+      const originalPlay = mediaPrototype.play;
+      mediaPrototype.play = function mediaGuardedPlay(this: GuardableMediaElement): Promise<void> {
+        this.muted = true;
+        this.defaultMuted = true;
+        if (typeof this.volume === 'number') {
+          this.volume = 0;
+        }
+        this.pause?.();
+        return Promise.resolve();
+      };
+      mediaPrototype.__wppSecondaryDeviceAudioGuard__ = {
+        originalPlay,
+        installs: 1,
+      };
+    }
+
+    this.restoreAudioGuard = () => {
+      const currentState = mediaPrototype.__wppSecondaryDeviceAudioGuard__;
+      if (!currentState) {
+        return;
+      }
+
+      currentState.installs -= 1;
+      if (currentState.installs <= 0) {
+        mediaPrototype.play = currentState.originalPlay;
+        delete mediaPrototype.__wppSecondaryDeviceAudioGuard__;
+      }
+    };
+  }
+
+
+  private silenceExistingMediaElements(): void {
+    if (typeof document === 'undefined' || typeof document.querySelectorAll !== 'function') {
+      return;
+    }
+
+    const activeElements = document.querySelectorAll('audio,video') as
+      | NodeListOf<HTMLMediaElement>
+      | GuardableMediaElement[]
+      | undefined;
+
+    if (!activeElements || typeof (activeElements as { forEach?: unknown }).forEach !== 'function') {
+      return;
+    }
+
+    activeElements.forEach((element) => {
+      element.muted = true;
+      element.defaultMuted = true;
+      if (typeof element.volume === 'number') {
+        element.volume = 0;
+      }
+      element.pause?.();
+    });
+  }
+
+  private scheduleStateSync(): void {
+    this.clearStateSyncTimer();
+
+    if (!this.sessionCode.trim() || this.connectionState !== 'online' || !this.session) {
+      return;
+    }
+
+    if (this.session.session.status === 'finished') {
+      return;
+    }
+
+    this.stateSyncTimer = setTimeout(() => {
+      this.stateSyncTimer = null;
+      if (this.loading || this.connectionState !== 'online') {
+        this.scheduleStateSync();
+        return;
+      }
+      void this.refreshSession();
+    }, 3000);
+  }
+
+  get showJoinControls(): boolean {
+    if (!this.session) {
+      return true;
+    }
+    return Boolean(this.session?.phase_view_model?.player?.can_join && !this.playerId && !this.sessionToken);
+  }
+
+  get showLieControls(): boolean {
+    return Boolean(this.session?.phase_view_model?.player?.can_submit_lie);
+  }
+
+  get showGuessControls(): boolean {
+    return Boolean(this.session?.phase_view_model?.player?.can_submit_guess);
+  }
+
+  get showFinalLeaderboard(): boolean {
+    return Boolean(this.session?.phase_view_model?.player?.can_view_final_result);
+  }
+
   get loadingMessage(): string {
     switch (this.loadingTransition) {
       case 'join':
-        return 'Joining session… restoring your player state.';
+        return this.copy('player.loading_join');
       case 'submit-lie':
-        return 'Submitting lie… waiting for guess phase.';
+        return this.copy('player.loading_submit_lie');
       case 'submit-guess':
-        return 'Submitting guess… waiting for reveal.';
+        return this.copy('player.loading_submit_guess');
       case 'refresh':
       default:
-        return 'Loading latest session state…';
+        return this.copy('player.loading_refresh');
     }
   }
 
+  copy(key: string): string {
+    return t(key, this.locale);
+  }
+
   private normalizeCode(value: string): string {
     return value.trim().toUpperCase();
   }
@@ -184,15 +389,18 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
     if (error instanceof Error && error.message) {
       return error.message;
     }
-    return 'Unknown error';
+    return this.copy('common.unknown_error');
   }
 
   private markOnline(): void {
     this.connectionState = 'online';
     this.clearReconnectTimer();
+    this.scheduleStateSync();
   }
 
   private markConnectionIssue(error: unknown): void {
+    this.clearStateSyncTimer();
+
     if (typeof navigator !== 'undefined' && !navigator.onLine) {
       this.connectionState = 'offline';
       return;
@@ -233,6 +441,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
   returnToJoin(): void {
     this.loadingTransition = null;
     this.clearReconnectTimer();
+    this.clearStateSyncTimer();
     this.connectionState = typeof navigator !== 'undefined' && !navigator.onLine ? 'offline' : 'online';
     this.session = null;
     this.finalLeaderboard = [];
@@ -259,6 +468,25 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
     });
   }
 
+  private syncRouteFromSession(): void {
+    if (!this.session) {
+      return;
+    }
+
+    const phase = this.gameplayPhase ?? this.session.session.status ?? 'lobby';
+    const code = this.normalizeCode(this.session.session.code || this.sessionCode);
+    if (!code) {
+      return;
+    }
+
+    const targetPath = `#/player/${encodeURIComponent(phase)}/${encodeURIComponent(code)}`;
+    if (typeof window === 'undefined' || window.location.hash === targetPath) {
+      return;
+    }
+
+    window.history.replaceState(window.history.state, '', targetPath);
+  }
+
   private async request<T>(path: string, method: 'GET' | 'POST', payload?: unknown): Promise<T> {
     const response = await fetch(path, {
       method,
@@ -285,7 +513,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
     try {
       const state = await this.controller.hydrateLobby(this.sessionCode);
       if (!state.session || state.errorMessage) {
-        throw new Error(state.errorMessage ?? 'Unknown error');
+        throw new Error(state.errorMessage ?? this.copy('common.unknown_error'));
       }
       this.session = state.session as SessionDetail;
       this.sessionCode = this.session.session.code;
@@ -293,9 +521,10 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
         this.selectedGuess = '';
       }
       this.syncFinalLeaderboard();
+      this.syncRouteFromSession();
       this.markOnline();
     } catch (error) {
-      this.error = `Session refresh failed: ${this.toMessage(error)}`;
+      this.error = `${this.copy('player.session_refresh_failed')}: ${this.toMessage(error)}`;
       this.markConnectionIssue(error);
     } finally {
       this.loading = false;
@@ -310,7 +539,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
     try {
       const state = await this.controller.joinLobby(this.sessionCode, this.nickname);
       if (!state.session || state.errorMessage) {
-        throw new Error(state.errorMessage ?? 'Unknown error');
+        throw new Error(state.errorMessage ?? this.copy('common.unknown_error'));
       }
       this.session = state.session as SessionDetail;
       this.sessionCode = this.session.session.code;
@@ -322,9 +551,10 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
         this.selectedGuess = '';
       }
       this.syncFinalLeaderboard();
+      this.syncRouteFromSession();
       this.markOnline();
     } catch (error) {
-      this.error = `Join failed: ${this.toMessage(error)}`;
+      this.error = `${this.copy('player.join_failed')}: ${this.toMessage(error)}`;
       this.markConnectionIssue(error);
     } finally {
       this.loading = false;
@@ -333,7 +563,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
   }
 
   async submitLie(): Promise<void> {
-    if (!this.session?.round_question?.id) {
+    if (!this.session?.round_question?.id || !this.canSubmitLie) {
       return;
     }
     this.loading = true;
@@ -352,7 +582,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
       await this.refreshSession();
       this.markOnline();
     } catch (error) {
-      this.submitError = { kind: 'lie', message: `Lie submit failed: ${this.toMessage(error)}` };
+      this.submitError = { kind: 'lie', message: `${this.copy('player.lie_submit_failed')}: ${this.toMessage(error)}` };
       this.markConnectionIssue(error);
     } finally {
       this.loading = false;
@@ -361,7 +591,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
   }
 
   async submitGuess(): Promise<void> {
-    if (!this.session?.round_question?.id || !this.selectedGuess) {
+    if (!this.session?.round_question?.id || !this.selectedGuess || !this.canSubmitGuess) {
       return;
     }
     this.loading = true;
@@ -380,7 +610,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
       await this.refreshSession();
       this.markOnline();
     } catch (error) {
-      this.submitError = { kind: 'guess', message: `Guess submit failed: ${this.toMessage(error)}` };
+      this.submitError = { kind: 'guess', message: `${this.copy('player.guess_submit_failed')}: ${this.toMessage(error)}` };
       this.markConnectionIssue(error);
     } finally {
       this.loading = false;

frontend/angular/src/app/gameplay-phase-machine.spec.ts

@@ -0,0 +1,96 @@
+import { describe, expect, it } from 'vitest';
+
+import { deriveGameplayPhase, transitionGameplayPhase } from '../../../src/spa/gameplay-phase-machine';
+
+describe('gameplay phase machine sync guards', () => {
+  it('keeps explicit scoreboard status as scoreboard phase', () => {
+    const phase = deriveGameplayPhase({
+      session: {
+        code: 'ABCD12',
+        status: 'scoreboard',
+        host_id: 1,
+        current_round: 1,
+        players_count: 2,
+      },
+      round_question: null,
+      players: [],
+      phase_view_model: {
+        status: 'scoreboard',
+        round_number: 1,
+        players_count: 2,
+        constraints: {
+          min_players_to_start: 2,
+          max_players_mvp: 8,
+          min_players_reached: true,
+          max_players_allowed: true,
+        },
+        host: {
+          can_start_round: false,
+          can_show_question: false,
+          can_mix_answers: false,
+          can_calculate_scores: false,
+          can_reveal_scoreboard: false,
+          can_start_next_round: true,
+          can_finish_game: true,
+        },
+        player: {
+          can_join: false,
+          can_submit_lie: false,
+          can_submit_guess: false,
+          can_view_final_result: false,
+        },
+      },
+    });
+
+    expect(phase).toBe('scoreboard');
+  });
+
+  it('maps finished status to scoreboard phase fallback', () => {
+    const phase = deriveGameplayPhase({
+      session: {
+        code: 'ABCD12',
+        status: 'finished',
+        host_id: 1,
+        current_round: 1,
+        players_count: 2,
+      },
+      round_question: null,
+      players: [],
+      phase_view_model: {
+        status: 'finished',
+        round_number: 1,
+        players_count: 2,
+        constraints: {
+          min_players_to_start: 2,
+          max_players_mvp: 8,
+          min_players_reached: true,
+          max_players_allowed: true,
+        },
+        host: {
+          can_start_round: false,
+          can_show_question: false,
+          can_mix_answers: false,
+          can_calculate_scores: false,
+          can_reveal_scoreboard: false,
+          can_start_next_round: false,
+          can_finish_game: false,
+        },
+        player: {
+          can_join: false,
+          can_submit_lie: false,
+          can_submit_guess: false,
+          can_view_final_result: true,
+        },
+      },
+    });
+
+    expect(phase).toBe('scoreboard');
+  });
+
+  it('transitions reveal -> scoreboard on SCOREBOARD_READY', () => {
+    expect(transitionGameplayPhase('reveal', 'SCOREBOARD_READY')).toEqual({
+      phase: 'scoreboard',
+      changed: true,
+    });
+  });
+});

frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts

@@ -0,0 +1,87 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+
+import { HostShellComponent } from './features/host/host-shell.component';
+import { PlayerShellComponent } from './features/player/player-shell.component';
+import { setPreferredLocale } from './lobby-i18n';
+
+function stubShellGlobals(initialLocale: string) {
+  vi.stubGlobal('window', {
+    location: { hash: '', search: '' },
+    history: { state: null, replaceState: vi.fn() },
+    localStorage: { getItem: vi.fn().mockReturnValue(initialLocale), setItem: vi.fn(), removeItem: vi.fn() },
+    sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+    addEventListener: vi.fn(),
+    removeEventListener: vi.fn(),
+  });
+  vi.stubGlobal('navigator', { language: `${initialLocale}-US`, onLine: true });
+}
+
+describe('i18n MVP flow smoke (host/player + audio policy)', () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+    vi.unstubAllGlobals();
+  });
+
+  it.each([
+    {
+      locale: 'en',
+      hostRefresh: 'Refresh',
+      hostStartRound: 'Start round',
+      playerSubmitGuess: 'Submit guess',
+    },
+    {
+      locale: 'da',
+      hostRefresh: 'Opdatér',
+      hostStartRound: 'Start runde',
+      playerSubmitGuess: 'Send gæt',
+    },
+  ])('resolves one host/player locale run for $locale', ({ locale, hostRefresh, hostStartRound, playerSubmitGuess }) => {
+    stubShellGlobals(locale);
+
+    const host = new HostShellComponent();
+    const player = new PlayerShellComponent();
+    host.ngOnInit();
+    player.ngOnInit();
+    setPreferredLocale(locale);
+
+    expect(host.copy('common.refresh')).toBe(hostRefresh);
+    expect(host.copy('game.host.start_round')).toBe(hostStartRound);
+    expect(player.copy('game.player.submit_guess')).toBe(playerSubmitGuess);
+
+    player.ngOnDestroy();
+    host.ngOnDestroy();
+  });
+
+  it('keeps audio routing primary-only by guarding player playback without muting the host path', async () => {
+    const originalPlay = vi.fn().mockRejectedValue(new Error('primary host playback'));
+    const mediaPrototype = { play: originalPlay };
+
+    vi.stubGlobal('window', {
+      location: { hash: '', search: '' },
+      history: { state: null, replaceState: vi.fn() },
+      localStorage: { getItem: vi.fn().mockReturnValue('en'), setItem: vi.fn(), removeItem: vi.fn() },
+      sessionStorage: { getItem: vi.fn().mockReturnValue(null), setItem: vi.fn(), removeItem: vi.fn() },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+      HTMLMediaElement: { prototype: mediaPrototype },
+    });
+    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
+    vi.stubGlobal('document', { querySelectorAll: vi.fn().mockReturnValue([]) });
+
+    const host = new HostShellComponent();
+    host.ngOnInit();
+
+    await expect(mediaPrototype.play()).rejects.toThrow('primary host playback');
+
+    const player = new PlayerShellComponent();
+    player.ngOnInit();
+
+    await expect(mediaPrototype.play()).resolves.toBeUndefined();
+
+    player.ngOnDestroy();
+
+    await expect(mediaPrototype.play()).rejects.toThrow('primary host playback');
+
+    host.ngOnDestroy();
+  });
+});

frontend/angular/src/app/lobby-i18n.spec.ts

@@ -0,0 +1,137 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+
+type StorageLike = {
+  getItem: (key: string) => string | null;
+  setItem: (key: string, value: string) => void;
+};
+
+function storageMock(initial: Record<string, string> = {}): StorageLike {
+  const data = new Map<string, string>(Object.entries(initial));
+  return {
+    getItem: vi.fn((key: string) => data.get(key) ?? null),
+    setItem: vi.fn((key: string, value: string) => {
+      data.set(key, value);
+    }),
+  };
+}
+
+describe('lobby i18n locale propagation', () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+    vi.unstubAllGlobals();
+    vi.resetModules();
+  });
+
+  it('notifies subscribers immediately and on locale changes', async () => {
+    const localStorage = storageMock({ 'wpp.locale': 'en' });
+    vi.stubGlobal('window', {
+      location: { search: '' },
+      localStorage,
+    });
+    vi.stubGlobal('navigator', { language: 'en-US' });
+
+    const i18n = await import('./lobby-i18n');
+
+    const updates: string[] = [];
+    const unsubscribe = i18n.subscribeToLocaleChanges((locale) => updates.push(locale));
+
+    expect(updates).toEqual(['en']);
+
+    i18n.setPreferredLocale('da');
+    expect(updates).toEqual(['en', 'da']);
+
+    unsubscribe();
+    i18n.setPreferredLocale('en');
+    expect(updates).toEqual(['en', 'da']);
+  });
+
+  it('prefers backend-provided shell locale over browser defaults', async () => {
+    vi.stubGlobal('window', {
+      location: { search: '' },
+      localStorage: storageMock(),
+    });
+    vi.stubGlobal('document', {
+      body: { dataset: { wppLocale: 'da' } },
+      querySelector: vi.fn(() => null),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US' });
+
+    const i18n = await import('./lobby-i18n');
+
+    expect(i18n.resolvePreferredLocale()).toBe('da');
+  });
+
+  it('falls back to default en translation when da key is intentionally missing', async () => {
+    vi.stubGlobal('window', {
+      location: { search: '' },
+      localStorage: storageMock({ 'wpp.locale': 'da' }),
+    });
+    vi.stubGlobal('navigator', { language: 'da-DK' });
+
+    const i18n = await import('./lobby-i18n');
+    const catalogModule = await import('../../../../shared/i18n/lobby.json');
+    const catalog = catalogModule.default as {
+      frontend: {
+        ui: {
+          common: {
+            refresh: {
+              en?: string;
+              da?: string;
+            };
+          };
+        };
+      };
+    };
+
+    const originalDa = catalog.frontend.ui.common.refresh.da;
+    catalog.frontend.ui.common.refresh.da = undefined;
+
+    try {
+      expect(i18n.t('common.refresh', 'da')).toBe(catalog.frontend.ui.common.refresh.en);
+    } finally {
+      catalog.frontend.ui.common.refresh.da = originalDa;
+    }
+  });
+
+  it('resolves baseline shell/game keys from shared namespaces', async () => {
+    vi.stubGlobal('window', {
+      location: { search: '' },
+      localStorage: storageMock({ 'wpp.locale': 'da' }),
+    });
+    vi.stubGlobal('navigator', { language: 'da-DK' });
+
+    const i18n = await import('./lobby-i18n');
+
+    const baselineKeys = [
+      'lobby.shell.title',
+      'lobby.shell.host_nav',
+      'lobby.shell.player_nav',
+      'lobby.shell.language_label',
+      'common.refresh',
+      'common.session_code',
+      'game.host.title',
+      'game.host.start_round',
+      'game.player.title',
+      'game.player.submit_guess',
+    ] as const;
+
+    for (const key of baselineKeys) {
+      const value = i18n.t(key, 'da');
+      expect(value).toBeTypeOf('string');
+      expect(value.length).toBeGreaterThan(0);
+      expect(value).not.toBe(key);
+    }
+  });
+
+  it('exposes primary-only audio routing policy to clients', async () => {
+    vi.stubGlobal('window', {
+      location: { search: '' },
+      localStorage: storageMock({ 'wpp.locale': 'en' }),
+    });
+    vi.stubGlobal('navigator', { language: 'en-US' });
+
+    const i18n = await import('./lobby-i18n');
+
+    expect(i18n.clientHasNoAudioOutput).toBe(true);
+  });
+});

frontend/angular/src/app/lobby-i18n.ts

@@ -0,0 +1,74 @@
+import {
+  DEFAULT_LOCALE,
+  LOBBY_I18N_CATALOG,
+  normalizeLocale,
+  type SupportedLocale,
+  translateCatalogPath,
+} from '../../../shared/i18n/lobby-loader';
+
+let activeLocale: SupportedLocale | null = null;
+const localeSubscribers = new Set<(locale: SupportedLocale) => void>();
+
+export { normalizeLocale };
+
+export function resolvePreferredLocale(): SupportedLocale {
+  if (activeLocale) {
+    return activeLocale;
+  }
+
+  if (typeof window === 'undefined') {
+    activeLocale = DEFAULT_LOCALE;
+    return activeLocale;
+  }
+
+  const rootLocale =
+    typeof document !== 'undefined' ? document.querySelector<HTMLElement>('app-root')?.dataset?.['wppLocale'] : null;
+  const shellLocale = typeof document !== 'undefined' ? document.body?.dataset?.['wppLocale'] : null;
+  const queryLocale = new URLSearchParams(window.location?.search ?? '').get('lang');
+  const storedLocale = window.localStorage?.getItem?.('wpp.locale');
+  const browserLocale = typeof navigator !== 'undefined' ? navigator.language : '';
+
+  activeLocale = normalizeLocale(rootLocale || shellLocale || queryLocale || storedLocale || browserLocale || DEFAULT_LOCALE);
+  return activeLocale;
+}
+
+export function setPreferredLocale(locale: string): SupportedLocale {
+  const normalized = normalizeLocale(locale);
+  activeLocale = normalized;
+  if (typeof window !== 'undefined') {
+    window.localStorage?.setItem?.('wpp.locale', normalized);
+  }
+
+  for (const subscriber of localeSubscribers) {
+    subscriber(normalized);
+  }
+
+  return normalized;
+}
+
+export function subscribeToLocaleChanges(callback: (locale: SupportedLocale) => void): () => void {
+  localeSubscribers.add(callback);
+  callback(resolvePreferredLocale());
+  return () => {
+    localeSubscribers.delete(callback);
+  };
+}
+
+function resolveCatalogPath(key: string): string {
+  if (key.startsWith('lobby.shell.')) {
+    return key.replace(/^lobby\.shell\./, 'app.');
+  }
+  if (key.startsWith('game.host.')) {
+    return key.replace(/^game\.host\./, 'host.');
+  }
+  if (key.startsWith('game.player.')) {
+    return key.replace(/^game\.player\./, 'player.');
+  }
+  return key;
+}
+
+export function t(key: string, locale: string): string {
+  return translateCatalogPath(LOBBY_I18N_CATALOG.frontend.ui as Record<string, unknown>, resolveCatalogPath(key), locale);
+}
+
+export const clientHasNoAudioOutput = Boolean(LOBBY_I18N_CATALOG.frontend.capabilities.client_has_no_audio_output);

frontend/angular/src/app/session-route-context.spec.ts

@@ -69,6 +69,7 @@ describe('session route context', () => {
       sessionCode: 'AB12',
       playerId: 5,
       token: 'tok-5',
+      locale: 'en',
     });
   });
 
@@ -80,7 +81,25 @@ describe('session route context', () => {
       sessionCode: 'AB12',
       playerId: null,
       token: null,
+      locale: 'en',
     });
     expect(sessionStorage.setItem).toHaveBeenCalledWith('wpp.host-session-code', 'AB12');
   });
+
+  it('resolvers normalize and expose locale from lang query param', () => {
+    setWindow(storageMock(), storageMock());
+
+    expect(hostRouteContextResolver(route({}, { lang: 'da-DK' }) as never, {} as never).locale).toBe('da');
+    expect(playerRouteContextResolver(route({}, { lang: 'EN' }) as never, {} as never).locale).toBe('en');
+  });
+
+  it('does not reset persisted preferred locale when lang query param is absent', () => {
+    const localStorage = storageMock({ 'wpp.locale': 'da' });
+    setWindow(localStorage, storageMock());
+
+    expect(hostRouteContextResolver(route({}, { lang: 'da' }) as never, {} as never).locale).toBe('da');
+    expect(hostRouteContextResolver(route({}, {}) as never, {} as never).locale).toBe('da');
+    expect(localStorage.setItem).toHaveBeenCalledTimes(1);
+    expect(localStorage.setItem).toHaveBeenCalledWith('wpp.locale', 'da');
+  });
 });

frontend/angular/src/app/session-route-context.ts

@@ -2,11 +2,13 @@ import { inject } from '@angular/core';
 import { type ActivatedRouteSnapshot, type CanActivateFn, type ResolveFn, Router, type UrlTree } from '@angular/router';
 
 import { createSessionContextStore } from '../../../src/spa/session-context-store';
+import { normalizeLocale, resolvePreferredLocale, setPreferredLocale } from './lobby-i18n';
 
 export interface RouteSessionContext {
   sessionCode: string | null;
   playerId: number | null;
   token: string | null;
+  locale: string;
 }
 
 const HOST_STORAGE_KEY = 'wpp.host-session-code';
@@ -61,6 +63,17 @@ export function resolveSessionCode(route: ActivatedRouteSnapshot, mode: 'host' |
   return null;
 }
 
+function resolveRouteLocale(route: ActivatedRouteSnapshot): string {
+  const langParam = route.queryParamMap.get('lang');
+  if (langParam !== null) {
+    const locale = normalizeLocale(langParam);
+    setPreferredLocale(locale);
+    return locale;
+  }
+
+  return resolvePreferredLocale();
+}
+
 async function sessionExists(code: string): Promise<boolean> {
   const response = await fetch(`/lobby/sessions/${encodeURIComponent(code)}`, {
     method: 'GET',
@@ -118,23 +131,26 @@ export const playerRouteGuard: CanActivateFn = (route) => guard('player', route)
 
 export const hostRouteContextResolver: ResolveFn<RouteSessionContext> = (route) => {
   const code = resolveSessionCode(route, 'host');
+  const locale = resolveRouteLocale(route);
   if (code) {
     window.sessionStorage.setItem(HOST_STORAGE_KEY, code);
   }
-  return { sessionCode: code, playerId: null, token: null };
+  return { sessionCode: code, playerId: null, token: null, locale };
 };
 
 export const playerRouteContextResolver: ResolveFn<RouteSessionContext> = (route) => {
   const code = resolveSessionCode(route, 'player');
+  const locale = resolveRouteLocale(route);
   const context = createSessionContextStore(window.localStorage).get();
 
   if (!code || !context || normalizeCode(context.sessionCode) !== code) {
-    return { sessionCode: code, playerId: null, token: null };
+    return { sessionCode: code, playerId: null, token: null, locale };
   }
 
   return {
     sessionCode: code,
     playerId: Number.isInteger(context.playerId) && context.playerId > 0 ? context.playerId : null,
     token: context.token.trim() || null,
+    locale,
   };
 };

frontend/angular/src/app/wpp-api-client.spec.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import { createWppApiClient } from './wpp-api-client';
+
+function jsonResponse(status: number, body: unknown) {
+  return {
+    ok: status >= 200 && status < 300,
+    status,
+    json: vi.fn().mockResolvedValue(body),
+  } as unknown as Response;
+}
+
+describe('WPP Angular API client skeleton', () => {
+  it('normalizes host/player API calls through fetch transport', async () => {
+    const fetchMock = vi
+      .fn()
+      .mockResolvedValueOnce(jsonResponse(200, { session: { code: 'ABCD12', status: 'lobby', host_id: 1, current_round: 1, players_count: 1 }, players: [], round_question: null, phase_view_model: { status: 'lobby', round_number: 1, players_count: 1, constraints: { min_players_to_start: 2, max_players_mvp: 8, min_players_reached: false, max_players_allowed: true }, host: { can_start_round: false, can_show_question: false, can_mix_answers: false, can_calculate_scores: false, can_reveal_scoreboard: false, can_start_next_round: false, can_finish_game: false }, player: { can_join: true, can_submit_lie: false, can_submit_guess: false, can_view_final_result: false } } }))
+      .mockResolvedValueOnce(jsonResponse(201, { player: { id: 1, nickname: 'Luna', session_token: 'tok', score: 0 }, session: { code: 'ABCD12', status: 'lobby' } }));
+
+    const client = createWppApiClient(fetchMock);
+
+    const session = await client.getSession(' abcd12 ');
+    const joined = await client.joinSession({ code: ' abcd12 ', nickname: ' Luna ' });
+
+    expect(session.ok).toBe(true);
+    expect(joined.ok).toBe(true);
+
+    expect(fetchMock).toHaveBeenNthCalledWith(
+      1,
+      '/lobby/sessions/ABCD12',
+      expect.objectContaining({ method: 'GET', credentials: 'same-origin' })
+    );
+    expect(fetchMock).toHaveBeenNthCalledWith(
+      2,
+      '/lobby/sessions/join',
+      expect.objectContaining({
+        method: 'POST',
+        credentials: 'same-origin',
+        body: JSON.stringify({ code: 'ABCD12', nickname: 'Luna' }),
+      })
+    );
+  });
+});

frontend/angular/src/app/wpp-api-client.ts

@@ -0,0 +1,58 @@
+import { InjectionToken } from '@angular/core';
+
+import {
+  createAngularApiClient,
+  type AngularApiClient,
+  type AngularHttpClientLike,
+} from '../../../src/api/angular-client';
+
+export const WPP_API_CLIENT = new InjectionToken<AngularApiClient>('WPP_API_CLIENT');
+
+export interface FetchLike {
+  (input: string, init?: RequestInit): Promise<Response>;
+}
+
+export function createFetchHttpClient(fetchImpl: FetchLike): AngularHttpClientLike {
+  return {
+    async get<T>(url: string): Promise<T> {
+      const response = await fetchImpl(url, {
+        method: 'GET',
+        headers: { Accept: 'application/json' },
+        credentials: 'same-origin',
+      });
+      const payload = await response.json().catch(() => ({}));
+      if (!response.ok) {
+        throw {
+          status: response.status,
+          message: (payload as { error?: string }).error ?? `HTTP ${response.status}`,
+          error: payload,
+        };
+      }
+      return payload as T;
+    },
+    async post<T>(url: string, body: unknown): Promise<T> {
+      const response = await fetchImpl(url, {
+        method: 'POST',
+        headers: {
+          Accept: 'application/json',
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify(body),
+        credentials: 'same-origin',
+      });
+      const payload = await response.json().catch(() => ({}));
+      if (!response.ok) {
+        throw {
+          status: response.status,
+          message: (payload as { error?: string }).error ?? `HTTP ${response.status}`,
+          error: payload,
+        };
+      }
+      return payload as T;
+    },
+  };
+}
+
+export function createWppApiClient(fetchImpl: FetchLike = fetch.bind(globalThis)): AngularApiClient {
+  return createAngularApiClient(createFetchHttpClient(fetchImpl));
+}

frontend/package-lock.json

@@ -7,12 +7,125 @@
     "": {
       "name": "wpp-frontend-api-client-baseline",
       "version": "0.1.0",
+      "dependencies": {
+        "@angular/common": "^19.2.0",
+        "@angular/compiler": "^19.2.0",
+        "@angular/core": "^19.2.0",
+        "@angular/forms": "^19.2.0",
+        "@angular/platform-browser": "^19.2.0",
+        "@angular/router": "^19.2.0",
+        "rxjs": "~7.8.0",
+        "tslib": "^2.3.0",
+        "zone.js": "~0.15.0"
+      },
       "devDependencies": {
         "@types/node": "^22.13.10",
         "typescript": "^5.7.3",
         "vitest": "^2.1.9"
       }
     },
+    "node_modules/@angular/common": {
+      "version": "19.2.20",
+      "resolved": "https://registry.npmjs.org/@angular/common/-/common-19.2.20.tgz",
+      "integrity": "sha512-1M3W3FjUUbVKXDMs+yQpBhnkD/pCe0Jn79rPE5W+EGWWxFoLSyGX+fhnRO5m4c9k66p3nvYrikWQ0ZzMv3M5tw==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.3.0"
+      },
+      "engines": {
+        "node": "^18.19.1 || ^20.11.1 || >=22.0.0"
+      },
+      "peerDependencies": {
+        "@angular/core": "19.2.20",
+        "rxjs": "^6.5.3 || ^7.4.0"
+      }
+    },
+    "node_modules/@angular/compiler": {
+      "version": "19.2.20",
+      "resolved": "https://registry.npmjs.org/@angular/compiler/-/compiler-19.2.20.tgz",
+      "integrity": "sha512-LvjE8W58EACgTFaAoqmNe7FRsbvoQ0GvCB/rmm6AEMWx/0W/JBvWkQTrOQlwpoeYOHcMZRGdmPcZoUDwU3JySQ==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.3.0"
+      },
+      "engines": {
+        "node": "^18.19.1 || ^20.11.1 || >=22.0.0"
+      }
+    },
+    "node_modules/@angular/core": {
+      "version": "19.2.20",
+      "resolved": "https://registry.npmjs.org/@angular/core/-/core-19.2.20.tgz",
+      "integrity": "sha512-pxzQh8ouqfE57lJlXjIzXFuRETwkfMVwS+NFCfv2yh01Qtx+vymO8ZClcJMgLPfBYinhBYX+hrRYVSa1nzlkRQ==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.3.0"
+      },
+      "engines": {
+        "node": "^18.19.1 || ^20.11.1 || >=22.0.0"
+      },
+      "peerDependencies": {
+        "rxjs": "^6.5.3 || ^7.4.0",
+        "zone.js": "~0.15.0"
+      }
+    },
+    "node_modules/@angular/forms": {
+      "version": "19.2.20",
+      "resolved": "https://registry.npmjs.org/@angular/forms/-/forms-19.2.20.tgz",
+      "integrity": "sha512-agi7InbMzop1jrud6L7SlNwnZk3iNolORcFIwBQMvKxLkcJ+ttbSYuM0KAw56IundWHf4dL9GP4cSygm4kUeFA==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.3.0"
+      },
+      "engines": {
+        "node": "^18.19.1 || ^20.11.1 || >=22.0.0"
+      },
+      "peerDependencies": {
+        "@angular/common": "19.2.20",
+        "@angular/core": "19.2.20",
+        "@angular/platform-browser": "19.2.20",
+        "rxjs": "^6.5.3 || ^7.4.0"
+      }
+    },
+    "node_modules/@angular/platform-browser": {
+      "version": "19.2.20",
+      "resolved": "https://registry.npmjs.org/@angular/platform-browser/-/platform-browser-19.2.20.tgz",
+      "integrity": "sha512-O9ZoQKILPC1T2c64OASS75XlOLBxY81m5AAgsBKhwiFWq+V28RsO0cnwpi1YSh/z4ryH8Fe7IUFz8jGrsJi3hQ==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.3.0"
+      },
+      "engines": {
+        "node": "^18.19.1 || ^20.11.1 || >=22.0.0"
+      },
+      "peerDependencies": {
+        "@angular/animations": "19.2.20",
+        "@angular/common": "19.2.20",
+        "@angular/core": "19.2.20"
+      },
+      "peerDependenciesMeta": {
+        "@angular/animations": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@angular/router": {
+      "version": "19.2.20",
+      "resolved": "https://registry.npmjs.org/@angular/router/-/router-19.2.20.tgz",
+      "integrity": "sha512-y0fyKycxJHr82kxXKE50Vac5hPn5Kx3gw9CfqyEuwJ9VQzEixDljU+chrQK4Wods14jJn9Tt2ncNPGH1rLya3Q==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.3.0"
+      },
+      "engines": {
+        "node": "^18.19.1 || ^20.11.1 || >=22.0.0"
+      },
+      "peerDependencies": {
+        "@angular/common": "19.2.20",
+        "@angular/core": "19.2.20",
+        "@angular/platform-browser": "19.2.20",
+        "rxjs": "^6.5.3 || ^7.4.0"
+      }
+    },
     "node_modules/@esbuild/aix-ppc64": {
       "version": "0.21.5",
       "resolved": "https://registry.npmjs.org/@esbuild/aix-ppc64/-/aix-ppc64-0.21.5.tgz",
@@ -1188,6 +1301,15 @@
         "fsevents": "~2.3.2"
       }
     },
+    "node_modules/rxjs": {
+      "version": "7.8.2",
+      "resolved": "https://registry.npmjs.org/rxjs/-/rxjs-7.8.2.tgz",
+      "integrity": "sha512-dhKf903U/PQZY6boNNtAGdWbG85WAbjT/1xYoZIC7FAY0yWapOBQVsVrDl58W86//e1VpMNBtRV4MaXfdMySFA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "tslib": "^2.1.0"
+      }
+    },
     "node_modules/siginfo": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/siginfo/-/siginfo-2.0.0.tgz",
@@ -1263,6 +1385,12 @@
         "node": ">=14.0.0"
       }
     },
+    "node_modules/tslib": {
+      "version": "2.8.1",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
+      "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
+      "license": "0BSD"
+    },
     "node_modules/typescript": {
       "version": "5.9.3",
       "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
@@ -1449,6 +1577,12 @@
       "engines": {
         "node": ">=8"
       }
+    },
+    "node_modules/zone.js": {
+      "version": "0.15.1",
+      "resolved": "https://registry.npmjs.org/zone.js/-/zone.js-0.15.1.tgz",
+      "integrity": "sha512-XE96n56IQpJM7NAoXswY3XRLcWFW83xe0BiAOeMD7K5k5xecOeul3Qcpx6GqEeeHNkW5DWL5zOyTbEfB4eti8w==",
+      "license": "MIT"
     }
   }
 }

frontend/package.json

@@ -7,6 +7,17 @@
     "test": "vitest run",
     "build": "tsc --noEmit"
   },
+  "dependencies": {
+    "@angular/common": "^19.2.0",
+    "@angular/compiler": "^19.2.0",
+    "@angular/core": "^19.2.0",
+    "@angular/forms": "^19.2.0",
+    "@angular/platform-browser": "^19.2.0",
+    "@angular/router": "^19.2.0",
+    "rxjs": "~7.8.0",
+    "tslib": "^2.3.0",
+    "zone.js": "~0.15.0"
+  },
   "devDependencies": {
     "@types/node": "^22.13.10",
     "typescript": "^5.7.3",

frontend/shared/i18n/lobby-loader.ts

@@ -0,0 +1,74 @@
+import lobbyCatalog from '../../../shared/i18n/lobby.json';
+
+export type LobbyCatalog = typeof lobbyCatalog;
+export type SupportedLocale = LobbyCatalog['locales']['supported'][number];
+
+export const LOBBY_I18N_CATALOG = lobbyCatalog;
+export const DEFAULT_LOCALE = lobbyCatalog.locales.default as SupportedLocale;
+export const SUPPORTED_LOCALES = lobbyCatalog.locales.supported as readonly SupportedLocale[];
+
+export function normalizeLocale(rawLocale?: string | null): SupportedLocale {
+  const locale = (rawLocale ?? '').trim().toLowerCase().replace(/_/g, '-');
+  if ((SUPPORTED_LOCALES as readonly string[]).includes(locale)) {
+    return locale as SupportedLocale;
+  }
+
+  const shortLocale = locale.split('-')[0] ?? '';
+  if ((SUPPORTED_LOCALES as readonly string[]).includes(shortLocale)) {
+    return shortLocale as SupportedLocale;
+  }
+
+  return DEFAULT_LOCALE;
+}
+
+export function translateCatalogPath(
+  root: Record<string, unknown>,
+  keyPath: string,
+  locale: string,
+  fallback = DEFAULT_LOCALE,
+): string {
+  const normalizedLocale = normalizeLocale(locale);
+  const segments = keyPath.split('.');
+
+  let cursor: unknown = root;
+  for (const segment of segments) {
+    if (!cursor || typeof cursor !== 'object' || !(segment in (cursor as Record<string, unknown>))) {
+      return keyPath;
+    }
+    cursor = (cursor as Record<string, unknown>)[segment];
+  }
+
+  if (!cursor || typeof cursor !== 'object') {
+    return keyPath;
+  }
+
+  const translations = cursor as Record<string, string>;
+  return translations[normalizedLocale] ?? translations[fallback] ?? keyPath;
+}
+
+export function collectLocaleParityIssues(
+  node: unknown,
+  locales: readonly string[] = SUPPORTED_LOCALES,
+  path = '',
+): string[] {
+  if (!node || typeof node !== 'object') {
+    return [];
+  }
+
+  const record = node as Record<string, unknown>;
+  const keys = Object.keys(record);
+  const isTranslationLeaf = keys.length > 0 && locales.every((locale) => locale in record);
+
+  if (isTranslationLeaf) {
+    const issues: string[] = [];
+    for (const locale of locales) {
+      const value = record[locale];
+      if (typeof value !== 'string' || !value.trim()) {
+        issues.push(`${path || '<root>'} missing non-empty '${locale}' translation`);
+      }
+    }
+    return issues;
+  }
+
+  return keys.flatMap((key) => collectLocaleParityIssues(record[key], locales, path ? `${path}.${key}` : key));
+}

frontend/src/api/client.ts

@@ -4,10 +4,10 @@ import {
   mapHealthResponse,
   mapJoinSessionResponse,
   mapMixAnswersResponse,
-  mapNextRoundResponse,
   mapScoreboardResponse,
   mapSessionDetailResponse,
   mapShowQuestionResponse,
+  mapStartNextRoundResponse,
   mapStartRoundResponse,
   mapSubmitGuessResponse,
   mapSubmitLieResponse
@@ -20,10 +20,10 @@ import type {
   JoinSessionRequest,
   JoinSessionResponse,
   MixAnswersResponse,
-  NextRoundResponse,
   ScoreboardResponse,
   SessionDetailResponse,
   ShowQuestionResponse,
+  StartNextRoundResponse,
   StartRoundRequest,
   StartRoundResponse,
   SubmitGuessRequest,
@@ -41,7 +41,7 @@ export interface ApiClient {
   mixAnswers(code: string, roundQuestionId: number): Promise<ApiResult<MixAnswersResponse>>;
   calculateScores(code: string, roundQuestionId: number): Promise<ApiResult<CalculateScoresResponse>>;
   getScoreboard(code: string): Promise<ApiResult<ScoreboardResponse>>;
-  startNextRound(code: string): Promise<ApiResult<NextRoundResponse>>;
+  startNextRound(code: string): Promise<ApiResult<StartNextRoundResponse>>;
   finishGame(code: string): Promise<ApiResult<FinishGameResponse>>;
   submitLie(code: string, roundQuestionId: number, payload: SubmitLieRequest): Promise<ApiResult<SubmitLieResponse>>;
   submitGuess(code: string, roundQuestionId: number, payload: SubmitGuessRequest): Promise<ApiResult<SubmitGuessResponse>>;
@@ -167,10 +167,10 @@ export function createApiClient(baseUrl = '', fetchImpl: typeof fetch = fetch):
         mapScoreboardResponse
       ),
     startNextRound: (code: string) =>
-      request<NextRoundResponse>(
+      request<StartNextRoundResponse>(
         `/lobby/sessions/${encodeURIComponent(normalizeCode(code))}/rounds/next`,
         'POST',
-        mapNextRoundResponse,
+        mapStartNextRoundResponse,
         {}
       ),
     finishGame: (code: string) =>

frontend/src/api/mappers.ts

@@ -60,6 +60,17 @@ function readBoolean(record: Record<string, unknown>, key: string, path: string)
   return value;
 }
 
+function readNullableNumber(record: Record<string, unknown>, key: string, path: string): number | null {
+  const value = record[key];
+  if (value === undefined || value === null) {
+    return null;
+  }
+  if (!isNumber(value)) {
+    throw new Error(`Invalid API contract: expected number|null at ${path}.${key}`);
+  }
+  return value;
+}
+
 export function mapHealthResponse(payload: unknown): HealthResponse {
   const root = asRecord(payload, 'health');
   return {
@@ -102,6 +113,58 @@ function mapSessionDetail(payload: unknown): SessionDetailResponse {
   const host = asRecord(phase.host, 'session_detail.phase_view_model.host');
   const player = asRecord(phase.player, 'session_detail.phase_view_model.player');
 
+  const revealRaw = root.reveal;
+  let reveal: SessionDetailResponse['reveal'] = null;
+  if (revealRaw !== null && revealRaw !== undefined) {
+    const revealRecord = asRecord(revealRaw, 'session_detail.reveal');
+    const liesRaw = revealRecord.lies;
+    const guessesRaw = revealRecord.guesses;
+    if (!Array.isArray(liesRaw)) {
+      throw new Error('Invalid API contract: expected array at session_detail.reveal.lies');
+    }
+    if (!Array.isArray(guessesRaw)) {
+      throw new Error('Invalid API contract: expected array at session_detail.reveal.guesses');
+    }
+
+    reveal = {
+      round_question_id: readNumber(revealRecord, 'round_question_id', 'session_detail.reveal'),
+      round_number: readNumber(revealRecord, 'round_number', 'session_detail.reveal'),
+      prompt: readString(revealRecord, 'prompt', 'session_detail.reveal'),
+      correct_answer: readString(revealRecord, 'correct_answer', 'session_detail.reveal'),
+      lies: liesRaw.map((lie, index) => {
+        const record = asRecord(lie, `session_detail.reveal.lies[${index}]`);
+        return {
+          player_id: readNumber(record, 'player_id', `session_detail.reveal.lies[${index}]`),
+          nickname: readString(record, 'nickname', `session_detail.reveal.lies[${index}]`),
+          text: readString(record, 'text', `session_detail.reveal.lies[${index}]`),
+          created_at: readString(record, 'created_at', `session_detail.reveal.lies[${index}]`)
+        };
+      }),
+      guesses: guessesRaw.map((guess, index) => {
+        const path = `session_detail.reveal.guesses[${index}]`;
+        const record = asRecord(guess, path);
+        const fooledPlayerId = readNullableNumber(record, 'fooled_player_id', path);
+        const fooledPlayerNickname = record.fooled_player_nickname;
+        if (fooledPlayerId === null) {
+          if (fooledPlayerNickname !== undefined) {
+            throw new Error(`Invalid API contract: expected ${path}.fooled_player_nickname to be omitted when fooled_player_id is null`);
+          }
+        } else if (!isString(fooledPlayerNickname)) {
+          throw new Error(`Invalid API contract: expected string at ${path}.fooled_player_nickname when fooled_player_id is set`);
+        }
+        return {
+          player_id: readNumber(record, 'player_id', path),
+          nickname: readString(record, 'nickname', path),
+          selected_text: readString(record, 'selected_text', path),
+          is_correct: readBoolean(record, 'is_correct', path),
+          fooled_player_id: fooledPlayerId,
+          ...(fooledPlayerNickname === undefined ? {} : { fooled_player_nickname: fooledPlayerNickname }),
+          created_at: readString(record, 'created_at', path)
+        };
+      })
+    };
+  }
+
   return {
     session: {
       code: readString(session, 'code', 'session_detail.session'),
@@ -129,8 +192,10 @@ function mapSessionDetail(payload: unknown): SessionDetailResponse {
       };
     }),
     round_question: roundQuestion,
+    reveal,
     phase_view_model: {
       status: readString(phase, 'status', 'session_detail.phase_view_model'),
+      current_phase: typeof phase.current_phase === 'string' ? phase.current_phase : undefined,
       round_number: readNumber(phase, 'round_number', 'session_detail.phase_view_model'),
       players_count: readNumber(phase, 'players_count', 'session_detail.phase_view_model'),
       constraints: {
@@ -139,6 +204,19 @@ function mapSessionDetail(payload: unknown): SessionDetailResponse {
         min_players_reached: readBoolean(constraints, 'min_players_reached', 'session_detail.phase_view_model.constraints'),
         max_players_allowed: readBoolean(constraints, 'max_players_allowed', 'session_detail.phase_view_model.constraints')
       },
+      readiness:
+        phase.readiness && typeof phase.readiness === 'object'
+          ? {
+              question_ready:
+                typeof (phase.readiness as Record<string, unknown>).question_ready === 'boolean'
+                  ? ((phase.readiness as Record<string, unknown>).question_ready as boolean)
+                  : undefined,
+              scoreboard_ready:
+                typeof (phase.readiness as Record<string, unknown>).scoreboard_ready === 'boolean'
+                  ? ((phase.readiness as Record<string, unknown>).scoreboard_ready as boolean)
+                  : undefined,
+            }
+          : undefined,
       host: {
         can_start_round: readBoolean(host, 'can_start_round', 'session_detail.phase_view_model.host'),
         can_show_question: readBoolean(host, 'can_show_question', 'session_detail.phase_view_model.host'),
@@ -337,10 +415,7 @@ export function mapSubmitGuessResponse(payload: unknown): SubmitGuessResponse {
   const root = asRecord(payload, 'submit_guess');
   const guess = asRecord(root.guess, 'submit_guess.guess');
   const window = asRecord(root.window, 'submit_guess.window');
-  const fooledPlayerId = guess.fooled_player_id;
-  if (fooledPlayerId !== null && !isNumber(fooledPlayerId)) {
-    throw new Error('Invalid API contract: expected number|null at submit_guess.guess.fooled_player_id');
-  }
+  const fooledPlayerId = readNullableNumber(guess, 'fooled_player_id', 'submit_guess.guess');
 
   return {
     guess: {

frontend/src/api/types.ts

@@ -32,6 +32,7 @@ export interface SessionRoundQuestion {
 
 export interface PhaseViewModel {
   status: string;
+  current_phase?: string;
   round_number: number;
   players_count: number;
   constraints: {
@@ -40,6 +41,10 @@ export interface PhaseViewModel {
     min_players_reached: boolean;
     max_players_allowed: boolean;
   };
+  readiness?: {
+    question_ready?: boolean;
+    scoreboard_ready?: boolean;
+  };
   host: {
     can_start_round: boolean;
     can_show_question: boolean;
@@ -57,10 +62,37 @@ export interface PhaseViewModel {
   };
 }
 
+export interface RevealLie {
+  player_id: number;
+  nickname: string;
+  text: string;
+  created_at: string;
+}
+
+export interface RevealGuess {
+  player_id: number;
+  nickname: string;
+  selected_text: string;
+  is_correct: boolean;
+  fooled_player_id: number | null;
+  fooled_player_nickname?: string;
+  created_at: string;
+}
+
+export interface RevealPayload {
+  round_question_id: number;
+  round_number: number;
+  prompt: string;
+  correct_answer: string;
+  lies: RevealLie[];
+  guesses: RevealGuess[];
+}
+
 export interface SessionDetailResponse {
   session: SessionSummary;
   players: SessionPlayer[];
   round_question: SessionRoundQuestion | null;
+  reveal: RevealPayload | null;
   phase_view_model: PhaseViewModel;
 }
 

frontend/src/spa/gameplay-phase-machine.ts

@@ -1,6 +1,15 @@
-import type { SessionDetailResponse } from '../api/types';
+import type { PhaseViewModel, SessionDetailResponse } from '../api/types';
 
 export type GameplayPhase = 'lie' | 'guess' | 'reveal' | 'scoreboard';
+export type HostGameplayAction =
+  | 'startRound'
+  | 'showQuestion'
+  | 'mixAnswers'
+  | 'calculateScores'
+  | 'loadScoreboard'
+  | 'startNextRound'
+  | 'finishGame';
+export type PlayerGameplayAction = 'join' | 'submitLie' | 'submitGuess' | 'viewFinalResult';
 
 export type GameplayPhaseEvent =
   | 'LIES_LOCKED'
@@ -40,13 +49,12 @@ export function allowedGameplayEvents(phase: GameplayPhase): GameplayPhaseEvent[
   return Object.keys(TRANSITIONS[phase]) as GameplayPhaseEvent[];
 }
 
-export function deriveGameplayPhase(session: SessionDetailResponse | null): GameplayPhase | null {
-  const status = session?.session.status;
+function derivePhaseFromStatus(status: string | null | undefined): GameplayPhase | null {
   if (!status) {
     return null;
   }
 
-  if (status === 'lie' || status === 'guess' || status === 'reveal') {
+  if (status === 'lie' || status === 'guess' || status === 'reveal' || status === 'scoreboard') {
     return status;
   }
 
@@ -56,3 +64,59 @@ export function deriveGameplayPhase(session: SessionDetailResponse | null): Game
 
   return null;
 }
+
+function deriveCanonicalPhaseStatus(phaseViewModel: PhaseViewModel | null | undefined): string | null {
+  if (!phaseViewModel) {
+    return null;
+  }
+
+  const currentPhase = (phaseViewModel as PhaseViewModel & { current_phase?: string }).current_phase;
+  return currentPhase ?? phaseViewModel.status ?? null;
+}
+
+export function deriveGameplayPhase(session: SessionDetailResponse | null): GameplayPhase | null {
+  const canonicalStatus = deriveCanonicalPhaseStatus(session?.phase_view_model);
+  return derivePhaseFromStatus(canonicalStatus ?? session?.session.status);
+}
+
+export function isHostGameplayActionAllowed(session: SessionDetailResponse | null, action: HostGameplayAction): boolean {
+  if (!session) {
+    return action === 'startRound';
+  }
+
+  const host = session.phase_view_model?.host;
+  switch (action) {
+    case 'startRound':
+      return Boolean(host?.can_start_round ?? false);
+    case 'showQuestion':
+      return Boolean(host?.can_show_question ?? false);
+    case 'mixAnswers':
+      return Boolean(host?.can_mix_answers ?? false);
+    case 'calculateScores':
+      return Boolean(host?.can_calculate_scores ?? false);
+    case 'loadScoreboard':
+      return Boolean(host?.can_reveal_scoreboard ?? false);
+    case 'startNextRound':
+      return Boolean(host?.can_start_next_round ?? false);
+    case 'finishGame':
+      return Boolean(host?.can_finish_game ?? false);
+  }
+}
+
+export function isPlayerGameplayActionAllowed(session: SessionDetailResponse | null, action: PlayerGameplayAction): boolean {
+  if (!session) {
+    return action === 'join';
+  }
+
+  const player = session.phase_view_model?.player;
+  switch (action) {
+    case 'join':
+      return Boolean(player?.can_join ?? false);
+    case 'submitLie':
+      return Boolean(player?.can_submit_lie ?? false);
+    case 'submitGuess':
+      return Boolean(player?.can_submit_guess ?? false);
+    case 'viewFinalResult':
+      return Boolean(player?.can_view_final_result ?? false);
+  }
+}

frontend/src/spa/lobby-i18n.ts

@@ -1,31 +1,48 @@
-import lobbyCatalog from '../../../shared/i18n/lobby.json';
+import { DEFAULT_LOCALE, LOBBY_I18N_CATALOG, normalizeLocale } from '../../shared/i18n/lobby-loader';
 
-type FrontendErrorKey = keyof typeof lobbyCatalog.frontend.errors;
+const frontendErrors = LOBBY_I18N_CATALOG.frontend.errors;
+const backendToFrontendErrorKeys = LOBBY_I18N_CATALOG.contract.backend_to_frontend_error_keys as Record<
+  string,
+  keyof typeof frontendErrors
+>;
 
-const frontendErrors = lobbyCatalog.frontend.errors;
+type FrontendErrorKey = keyof typeof frontendErrors;
 
-const apiErrorMap: Record<string, FrontendErrorKey> = {
-  session_code_required: 'session_code_required',
-  session_not_found: 'session_not_found',
-  nickname_invalid: 'nickname_invalid',
-  nickname_taken: 'nickname_taken'
-};
-
-export function lobbyMessage(key: FrontendErrorKey): string {
-  return frontendErrors[key] ?? frontendErrors.unknown;
+function isFrontendErrorKey(value: string): value is FrontendErrorKey {
+  return value in frontendErrors;
 }
 
-export function lobbyMessageFromApiPayload(payload: unknown, fallbackKey: FrontendErrorKey): string {
+export function lobbyMessage(key: FrontendErrorKey, locale?: string): string {
+  const resolvedLocale = normalizeLocale(locale);
+  const translations = frontendErrors[key] as Record<string, string>;
+
+  if (translations[resolvedLocale]) {
+    return translations[resolvedLocale];
+  }
+  if (translations[DEFAULT_LOCALE]) {
+    return translations[DEFAULT_LOCALE];
+  }
+
+  return key;
+}
+
+export function lobbyMessageFromApiPayload(payload: unknown, fallbackKey: FrontendErrorKey, locale?: string): string {
   if (!payload || typeof payload !== 'object') {
-    return lobbyMessage(fallbackKey);
+    return lobbyMessage(fallbackKey, locale);
   }
 
   const record = payload as Record<string, unknown>;
   const code = typeof record.error_code === 'string' ? record.error_code : '';
-  const mappedKey = apiErrorMap[code];
-  if (!mappedKey) {
-    return lobbyMessage(fallbackKey);
+  const payloadLocale = typeof record.locale === 'string' ? record.locale : locale;
+  const mappedKey = code ? backendToFrontendErrorKeys[code] : undefined;
+
+  if (mappedKey && isFrontendErrorKey(mappedKey)) {
+    return lobbyMessage(mappedKey, payloadLocale);
   }
 
-  return lobbyMessage(mappedKey);
+  if (isFrontendErrorKey(code)) {
+    return lobbyMessage(code, payloadLocale);
+  }
+
+  return lobbyMessage(fallbackKey, payloadLocale);
 }

frontend/tests/angular-api-client.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it, vi } from 'vitest';
 
 import { createAngularApiClient, type AngularHttpClientLike } from '../src/api/angular-client';
+import { mapSessionDetailResponse, mapSubmitGuessResponse } from '../src/api/mappers';
 
 describe('createAngularApiClient', () => {
   it('reads health and session detail using Django-compatible endpoints', async () => {
@@ -206,11 +207,391 @@ describe('createAngularApiClient', () => {
     }
   });
 
+  it('keeps canonical reveal payload stable when session detail is already in scoreboard phase', async () => {
+    const get = vi.fn<AngularHttpClientLike['get']>(async <T>(url: string) => {
+      if (url === '/lobby/sessions/ABCD12') {
+        return {
+          session: { code: 'ABCD12', status: 'scoreboard', host_id: 1, current_round: 1, players_count: 2 },
+          players: [
+            { id: 2, nickname: 'Maja', score: 10, is_connected: true },
+            { id: 3, nickname: 'Bo', score: 7, is_connected: true }
+          ],
+          round_question: {
+            id: 77,
+            round_number: 1,
+            prompt: 'Q?',
+            shown_at: '2026-03-01T18:00:00Z',
+            answers: [{ text: 'A' }, { text: 'B' }]
+          },
+          reveal: {
+            round_question_id: 77,
+            round_number: 1,
+            prompt: 'Q?',
+            correct_answer: 'A',
+            lies: [{ player_id: 2, nickname: 'Maja', text: 'B', created_at: '2026-03-01T18:00:05Z' }],
+            guesses: [
+              {
+                player_id: 3,
+                nickname: 'Bo',
+                selected_text: 'B',
+                is_correct: false,
+                fooled_player_id: 2,
+                fooled_player_nickname: 'Maja',
+                created_at: '2026-03-01T18:00:15Z'
+              }
+            ]
+          },
+          phase_view_model: {
+            status: 'scoreboard',
+            round_number: 1,
+            players_count: 2,
+            constraints: {
+              min_players_to_start: 2,
+              max_players_mvp: 8,
+              min_players_reached: true,
+              max_players_allowed: true
+            },
+            host: {
+              can_start_round: false,
+              can_show_question: false,
+              can_mix_answers: false,
+              can_calculate_scores: false,
+              can_reveal_scoreboard: false,
+              can_start_next_round: true,
+              can_finish_game: true
+            },
+            player: {
+              can_join: true,
+              can_submit_lie: false,
+              can_submit_guess: false,
+              can_view_final_result: false
+            }
+          }
+        } as T;
+      }
+      throw { status: 404, error: { error: 'Not found' } };
+    });
+
+    const client = createAngularApiClient({ get, post: vi.fn() } as unknown as AngularHttpClientLike);
+    const session = await client.getSession('abcd12');
+
+    expect(session.ok).toBe(true);
+    if (session.ok) {
+      expect(session.data.session.status).toBe('scoreboard');
+      expect(session.data.reveal?.guesses[0].fooled_player_nickname).toBe('Maja');
+      expect(session.data.phase_view_model.host.can_start_next_round).toBe(true);
+      expect(session.data.phase_view_model.host.can_finish_game).toBe(true);
+    }
+  });
+
+  it('normalizes omitted fooled_player_id to null in canonical reveal payloads', async () => {
+    const get = vi.fn<AngularHttpClientLike['get']>(async <T>(url: string) => {
+      if (url === '/lobby/sessions/ABCD12') {
+        return {
+          session: { code: 'ABCD12', status: 'reveal', host_id: 1, current_round: 1, players_count: 2 },
+          players: [
+            { id: 2, nickname: 'Maja', score: 10, is_connected: true },
+            { id: 3, nickname: 'Bo', score: 7, is_connected: true }
+          ],
+          round_question: {
+            id: 77,
+            round_number: 1,
+            prompt: 'Q?',
+            shown_at: '2026-03-01T18:00:00Z',
+            answers: [{ text: 'A' }, { text: 'B' }]
+          },
+          reveal: {
+            round_question_id: 77,
+            round_number: 1,
+            prompt: 'Q?',
+            correct_answer: 'A',
+            lies: [],
+            guesses: [
+              {
+                player_id: 3,
+                nickname: 'Bo',
+                selected_text: 'A',
+                is_correct: true,
+                created_at: '2026-03-01T18:00:15Z'
+              }
+            ]
+          },
+          phase_view_model: {
+            status: 'reveal',
+            round_number: 1,
+            players_count: 2,
+            constraints: {
+              min_players_to_start: 2,
+              max_players_mvp: 8,
+              min_players_reached: true,
+              max_players_allowed: true
+            },
+            host: {
+              can_start_round: false,
+              can_show_question: false,
+              can_mix_answers: false,
+              can_calculate_scores: false,
+              can_reveal_scoreboard: true,
+              can_start_next_round: false,
+              can_finish_game: false
+            },
+            player: {
+              can_join: true,
+              can_submit_lie: false,
+              can_submit_guess: false,
+              can_view_final_result: false
+            }
+          }
+        } as T;
+      }
+      throw { status: 404, error: { error: 'Not found' } };
+    });
+
+    const post = vi.fn<AngularHttpClientLike['post']>(async <T>(url: string, body: unknown) => {
+      if (url === '/lobby/sessions/ABCD12/questions/77/guesses/submit') {
+        expect(body).toEqual({ player_id: 9, session_token: 'tok', selected_text: 'A' });
+        return {
+          guess: {
+            id: 200,
+            player_id: 9,
+            round_question_id: 77,
+            selected_text: 'A',
+            is_correct: false,
+            created_at: '2026-03-01T16:01:00Z'
+          },
+          window: { guess_deadline_at: '2026-03-01T16:01:30Z' }
+        } as T;
+      }
+      throw { status: 404, error: { error: 'Not found' } };
+    });
+
+    const client = createAngularApiClient({ get, post } as AngularHttpClientLike);
+    const session = await client.getSession('abcd12');
+
+    expect(session.ok).toBe(true);
+    if (session.ok) {
+      expect(session.data.reveal?.guesses[0].fooled_player_id).toBeNull();
+      expect(session.data.reveal?.guesses[0]).not.toHaveProperty('fooled_player_nickname');
+    }
+
+    const submitGuess = await client.submitGuess('ABCD12', 77, {
+      player_id: 9,
+      session_token: 'tok',
+      selected_text: 'A'
+    });
+    expect(submitGuess.ok).toBe(true);
+    if (submitGuess.ok) {
+      expect(submitGuess.data.guess.fooled_player_id).toBeNull();
+    }
+  });
+
+  it('maps omitted fooled_player_id to null in submit guess mapper payloads', () => {
+    const mapped = mapSubmitGuessResponse({
+      guess: {
+        id: 200,
+        player_id: 9,
+        round_question_id: 77,
+        selected_text: 'A',
+        is_correct: false,
+        created_at: '2026-03-01T16:01:00Z'
+      },
+      window: { guess_deadline_at: '2026-03-01T16:01:30Z' }
+    });
+
+    expect(mapped.guess.fooled_player_id).toBeNull();
+  });
+
+  it('keeps fooled_player_nickname omitted when canonical reveal payload omits fooled player refs', () => {
+    const mapped = mapSessionDetailResponse({
+      session: { code: 'ABCD12', status: 'reveal', host_id: 1, current_round: 1, players_count: 2 },
+      players: [
+        { id: 2, nickname: 'Maja', score: 10, is_connected: true },
+        { id: 3, nickname: 'Bo', score: 7, is_connected: true }
+      ],
+      round_question: {
+        id: 77,
+        round_number: 1,
+        prompt: 'Q?',
+        shown_at: '2026-03-01T18:00:00Z',
+        answers: [{ text: 'A' }, { text: 'B' }]
+      },
+      reveal: {
+        round_question_id: 77,
+        round_number: 1,
+        prompt: 'Q?',
+        correct_answer: 'A',
+        lies: [],
+        guesses: [
+          {
+            player_id: 3,
+            nickname: 'Bo',
+            selected_text: 'A',
+            is_correct: true,
+            created_at: '2026-03-01T18:00:15Z'
+          }
+        ]
+      },
+      phase_view_model: {
+        status: 'reveal',
+        round_number: 1,
+        players_count: 2,
+        constraints: {
+          min_players_to_start: 2,
+          max_players_mvp: 8,
+          min_players_reached: true,
+          max_players_allowed: true
+        },
+        host: {
+          can_start_round: false,
+          can_show_question: false,
+          can_mix_answers: false,
+          can_calculate_scores: false,
+          can_reveal_scoreboard: true,
+          can_start_next_round: false,
+          can_finish_game: false
+        },
+        player: {
+          can_join: true,
+          can_submit_lie: false,
+          can_submit_guess: false,
+          can_view_final_result: false
+        }
+      }
+    });
+
+    expect(mapped.reveal?.guesses[0].fooled_player_id).toBeNull();
+    expect(mapped.reveal?.guesses[0]).not.toHaveProperty('fooled_player_nickname');
+  });
+
+  it('rejects canonical reveal payloads that include fooled_player_nickname without fooled_player_id', () => {
+    expect(() =>
+      mapSessionDetailResponse({
+        session: { code: 'ABCD12', status: 'reveal', host_id: 1, current_round: 1, players_count: 2 },
+        players: [
+          { id: 2, nickname: 'Maja', score: 10, is_connected: true },
+          { id: 3, nickname: 'Bo', score: 7, is_connected: true }
+        ],
+        round_question: {
+          id: 77,
+          round_number: 1,
+          prompt: 'Q?',
+          shown_at: '2026-03-01T18:00:00Z',
+          answers: [{ text: 'A' }, { text: 'B' }]
+        },
+        reveal: {
+          round_question_id: 77,
+          round_number: 1,
+          prompt: 'Q?',
+          correct_answer: 'A',
+          lies: [],
+          guesses: [
+            {
+              player_id: 3,
+              nickname: 'Bo',
+              selected_text: 'A',
+              is_correct: true,
+              fooled_player_nickname: 'Maja',
+              created_at: '2026-03-01T18:00:15Z'
+            }
+          ]
+        },
+        phase_view_model: {
+          status: 'reveal',
+          round_number: 1,
+          players_count: 2,
+          constraints: {
+            min_players_to_start: 2,
+            max_players_mvp: 8,
+            min_players_reached: true,
+            max_players_allowed: true
+          },
+          host: {
+            can_start_round: false,
+            can_show_question: false,
+            can_mix_answers: false,
+            can_calculate_scores: false,
+            can_reveal_scoreboard: true,
+            can_start_next_round: false,
+            can_finish_game: false
+          },
+          player: {
+            can_join: true,
+            can_submit_lie: false,
+            can_submit_guess: false,
+            can_view_final_result: false
+          }
+        }
+      })
+    ).toThrow('fooled_player_nickname to be omitted when fooled_player_id is null');
+  });
+
+  it('rejects canonical reveal payloads that omit fooled_player_nickname when fooled_player_id is set', () => {
+    expect(() =>
+      mapSessionDetailResponse({
+        session: { code: 'ABCD12', status: 'reveal', host_id: 1, current_round: 1, players_count: 2 },
+        players: [
+          { id: 2, nickname: 'Maja', score: 10, is_connected: true },
+          { id: 3, nickname: 'Bo', score: 7, is_connected: true }
+        ],
+        round_question: {
+          id: 77,
+          round_number: 1,
+          prompt: 'Q?',
+          shown_at: '2026-03-01T18:00:00Z',
+          answers: [{ text: 'A' }, { text: 'B' }]
+        },
+        reveal: {
+          round_question_id: 77,
+          round_number: 1,
+          prompt: 'Q?',
+          correct_answer: 'A',
+          lies: [],
+          guesses: [
+            {
+              player_id: 3,
+              nickname: 'Bo',
+              selected_text: 'B',
+              is_correct: false,
+              fooled_player_id: 2,
+              created_at: '2026-03-01T18:00:15Z'
+            }
+          ]
+        },
+        phase_view_model: {
+          status: 'reveal',
+          round_number: 1,
+          players_count: 2,
+          constraints: {
+            min_players_to_start: 2,
+            max_players_mvp: 8,
+            min_players_reached: true,
+            max_players_allowed: true
+          },
+          host: {
+            can_start_round: false,
+            can_show_question: false,
+            can_mix_answers: false,
+            can_calculate_scores: false,
+            can_reveal_scoreboard: true,
+            can_start_next_round: false,
+            can_finish_game: false
+          },
+          player: {
+            can_join: true,
+            can_submit_lie: false,
+            can_submit_guess: false,
+            can_view_final_result: false
+          }
+        }
+      })
+    ).toThrow('fooled_player_nickname when fooled_player_id is set');
+  });
+
   it('maps host/player gameplay endpoints through typed response mappers', async () => {
     const get = vi.fn<AngularHttpClientLike['get']>(async <T>(url: string) => {
       if (url === '/lobby/sessions/ABCD12/scoreboard') {
         return {
-          session: { code: 'ABCD12', status: 'reveal', current_round: 1 },
+          session: { code: 'ABCD12', status: 'scoreboard', current_round: 1 },
           leaderboard: [
             { id: 2, nickname: 'Maja', score: 11 },
             { id: 3, nickname: 'Bo', score: 7 }
@@ -245,7 +626,7 @@ describe('createAngularApiClient', () => {
       if (url === '/lobby/sessions/ABCD12/questions/77/scores/calculate') {
         expect(body).toEqual({});
         return {
-          session: { code: 'ABCD12', status: 'reveal', current_round: 1 },
+          session: { code: 'ABCD12', status: 'scoreboard', current_round: 1 },
           round_question: { id: 77, round_number: 1 },
           events_created: 3,
           leaderboard: [{ id: 2, nickname: 'Maja', score: 11 }]
@@ -253,7 +634,7 @@ describe('createAngularApiClient', () => {
       }
       if (url === '/lobby/sessions/ABCD12/rounds/next') {
         expect(body).toEqual({});
-        return { session: { code: 'ABCD12', status: 'lobby', current_round: 2 } } as T;
+        return { session: { code: 'ABCD12', status: 'lie', current_round: 2 } } as T;
       }
       if (url === '/lobby/sessions/ABCD12/finish') {
         expect(body).toEqual({});

frontend/tests/gameplay-phase-machine.test.ts

@@ -2,6 +2,8 @@ import { describe, expect, it } from 'vitest';
 import {
   allowedGameplayEvents,
   deriveGameplayPhase,
+  isHostGameplayActionAllowed,
+  isPlayerGameplayActionAllowed,
   transitionGameplayPhase,
   type GameplayPhase
 } from '../src/spa/gameplay-phase-machine';
@@ -40,6 +42,7 @@ describe('gameplay phase machine skeleton', () => {
         session: { code: 'ABCD12', status: 'lie', host_id: 1, current_round: 1, players_count: 3 },
         players: [],
         round_question: null,
+        reveal: null,
         phase_view_model: {
           status: 'lie',
           round_number: 1,
@@ -74,6 +77,7 @@ describe('gameplay phase machine skeleton', () => {
         session: { code: 'ABCD12', status: 'finished', host_id: 1, current_round: 1, players_count: 3 },
         players: [],
         round_question: null,
+        reveal: null,
         phase_view_model: {
           status: 'finished',
           round_number: 1,
@@ -103,4 +107,44 @@ describe('gameplay phase machine skeleton', () => {
       })
     ).toBe('scoreboard');
   });
+
+  it('gates host and player actions from canonical phase_view_model permissions', () => {
+    const session = {
+      session: { code: 'ABCD12', status: 'scoreboard', host_id: 1, current_round: 1, players_count: 3 },
+      players: [],
+      round_question: { id: 77, prompt: 'Q?', answers: [] },
+      phase_view_model: {
+        status: 'reveal',
+        round_number: 1,
+        players_count: 3,
+        constraints: {
+          min_players_to_start: 3,
+          max_players_mvp: 5,
+          min_players_reached: true,
+          max_players_allowed: true
+        },
+        host: {
+          can_start_round: false,
+          can_show_question: false,
+          can_mix_answers: false,
+          can_calculate_scores: false,
+          can_reveal_scoreboard: true,
+          can_start_next_round: true,
+          can_finish_game: true
+        },
+        player: {
+          can_join: false,
+          can_submit_lie: false,
+          can_submit_guess: false,
+          can_view_final_result: false
+        }
+      }
+    } as const;
+
+    expect(deriveGameplayPhase(session as any)).toBe('reveal');
+    expect(isHostGameplayActionAllowed(session as any, 'loadScoreboard')).toBe(true);
+    expect(isHostGameplayActionAllowed(session as any, 'startNextRound')).toBe(true);
+    expect(isHostGameplayActionAllowed(session as any, 'finishGame')).toBe(true);
+    expect(isPlayerGameplayActionAllowed(session as any, 'submitGuess')).toBe(false);
+  });
 });

frontend/tests/lobby-i18n.contract.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, it } from 'vitest';
+
+import lobbyCatalog from '../../shared/i18n/lobby.json';
+import { lobbyMessage, lobbyMessageFromApiPayload } from '../src/spa/lobby-i18n';
+
+describe('shared i18n keyspace contract', () => {
+  it('keeps en as default and da/en matrix for frontend error keys', () => {
+    expect(lobbyCatalog.locales.default).toBe('en');
+    expect(lobbyCatalog.locales.supported).toEqual(expect.arrayContaining(['en', 'da']));
+
+    for (const [key, translations] of Object.entries(lobbyCatalog.frontend.errors)) {
+      expect(translations.en, `${key} missing en`).toBeTruthy();
+      expect(translations.da, `${key} missing da`).toBeTruthy();
+    }
+  });
+
+  it('keeps backend error-code keyspace aligned with shared backend→frontend map and backend translations', () => {
+    for (const [code, backendKey] of Object.entries(lobbyCatalog.backend.error_codes)) {
+      const frontendKey =
+        lobbyCatalog.contract.backend_to_frontend_error_keys[
+          code as keyof typeof lobbyCatalog.contract.backend_to_frontend_error_keys
+        ];
+
+      expect(lobbyCatalog.backend.errors[backendKey as keyof typeof lobbyCatalog.backend.errors]).toBeDefined();
+      expect(frontendKey, `missing frontend mapping for ${code}`).toBeTruthy();
+      expect(lobbyCatalog.frontend.errors[frontendKey as keyof typeof lobbyCatalog.frontend.errors]).toBeDefined();
+    }
+
+    for (const [key, translations] of Object.entries(lobbyCatalog.backend.errors)) {
+      expect(translations.en, `${key} missing en`).toBeTruthy();
+      expect(translations.da, `${key} missing da`).toBeTruthy();
+    }
+  });
+});
+
+describe('lobbyMessage locale handling', () => {
+  it('uses english by default and falls back to default for unsupported locale', () => {
+    expect(lobbyMessage('session_code_required')).toBe('Session code is required.');
+    expect(lobbyMessage('session_code_required', 'fr')).toBe('Session code is required.');
+  });
+
+  it('resolves locale from api payload and maps known backend error codes directly', () => {
+    expect(
+      lobbyMessageFromApiPayload(
+        { error_code: 'session_not_found', locale: 'da' },
+        'join_failed',
+      ),
+    ).toBe('Sessionskoden er ugyldig, eller sessionen findes ikke længere.');
+  });
+
+  it('uses shared backend→frontend key-map at runtime even when fallback key differs', () => {
+    expect(
+      lobbyMessageFromApiPayload(
+        { error_code: 'session_not_joinable', locale: 'da' },
+        'start_round_failed',
+      ),
+    ).toBe('Kunne ikke joine. Tjek kode eller kaldenavn og prøv igen.');
+  });
+
+  it('falls back to caller-provided fallback key for unknown backend error codes', () => {
+    expect(
+      lobbyMessageFromApiPayload(
+        { error_code: 'unknown_backend_key', locale: 'da' },
+        'join_failed',
+      ),
+    ).toBe('Kunne ikke joine. Tjek kode eller kaldenavn og prøv igen.');
+  });
+});

frontend/tests/lobby-loader.parity.test.ts

@@ -0,0 +1,38 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  collectLocaleParityIssues,
+  LOBBY_I18N_CATALOG,
+  normalizeLocale,
+  SUPPORTED_LOCALES,
+  translateCatalogPath,
+} from '../shared/i18n/lobby-loader';
+
+describe('shared lobby i18n loader parity', () => {
+  it('keeps da/en translation parity in shared keyspace', () => {
+    const issues = collectLocaleParityIssues(LOBBY_I18N_CATALOG, SUPPORTED_LOCALES);
+    expect(issues).toEqual([]);
+  });
+
+  it('normalizes browser-style locale tags to supported keyspace locales', () => {
+    expect(normalizeLocale('da-DK')).toBe('da');
+    expect(normalizeLocale('da_DK')).toBe('da');
+    expect(normalizeLocale('en-US')).toBe('en');
+    expect(normalizeLocale('en_US')).toBe('en');
+    expect(normalizeLocale('fr-FR')).toBe('en');
+  });
+
+  it('resolves shared frontend ui keys with fallback-safe behavior', () => {
+    expect(
+      translateCatalogPath(LOBBY_I18N_CATALOG.frontend.ui as Record<string, unknown>, 'host.start_round', 'da-DK'),
+    ).toBe('Start runde');
+
+    expect(
+      translateCatalogPath(LOBBY_I18N_CATALOG.frontend.ui as Record<string, unknown>, 'app.language_label', 'en-US'),
+    ).toBe('Language');
+
+    expect(
+      translateCatalogPath(LOBBY_I18N_CATALOG.frontend.ui as Record<string, unknown>, 'host.non_existing_key', 'da'),
+    ).toBe('host.non_existing_key');
+  });
+});

frontend/tests/vertical-slice.test.ts

@@ -16,6 +16,7 @@ function makeApiMock(overrides?: Partial<ApiClient>): ApiClient {
         session: { code: 'ABCD12', status: 'lobby', host_id: 1, current_round: 1, players_count: 3 },
         players: [],
         round_question: null,
+        reveal: null,
         phase_view_model: {
           status: 'lobby',
           round_number: 1,
@@ -56,7 +57,15 @@ function makeApiMock(overrides?: Partial<ApiClient>): ApiClient {
         session: { code: 'ABCD12', status: 'lie', current_round: 1 },
         round: { number: 1, category: { slug: 'history', name: 'History' } }
       }
-    })
+    }),
+    showQuestion: vi.fn(),
+    mixAnswers: vi.fn(),
+    calculateScores: vi.fn(),
+    getScoreboard: vi.fn(),
+    startNextRound: vi.fn(),
+    finishGame: vi.fn(),
+    submitLie: vi.fn(),
+    submitGuess: vi.fn()
   };
 
   return { ...base, ...overrides };

frontend/vitest.config.ts

@@ -2,7 +2,8 @@ import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
   test: {
-    include: ['tests/**/*.test.ts'],
+    include: ['tests/**/*.test.ts', 'angular/src/**/*.spec.ts'],
+    setupFiles: ['angular/src/test-setup.ts'],
     exclude: ['**/node_modules/**']
   }
 });

fupogfakta/migrations/0005_alter_gamesession_status.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0.2 on 2026-03-13 16:05
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('fupogfakta', '0004_player_session_token'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='gamesession',
+            name='status',
+            field=models.CharField(choices=[('lobby', 'Lobby'), ('lie', 'Løgnfase'), ('guess', 'Gættefase'), ('reveal', 'Reveal'), ('scoreboard', 'Scoreboard'), ('finished', 'Afsluttet')], default='lobby', max_length=16),
+        ),
+    ]

fupogfakta/migrations/0005_gamesession_scoreboard_status.py

@@ -0,0 +1,26 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("fupogfakta", "0004_player_session_token"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="gamesession",
+            name="status",
+            field=models.CharField(
+                choices=[
+                    ("lobby", "Lobby"),
+                    ("lie", "Løgnfase"),
+                    ("guess", "Gættefase"),
+                    ("reveal", "Reveal"),
+                    ("scoreboard", "Scoreboard"),
+                    ("finished", "Afsluttet"),
+                ],
+                default="lobby",
+                max_length=16,
+            ),
+        ),
+    ]

fupogfakta/migrations/0006_merge_20260315_1249.py

@@ -0,0 +1,10 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("fupogfakta", "0005_alter_gamesession_status"),
+        ("fupogfakta", "0005_gamesession_scoreboard_status"),
+    ]
+
+    operations = []

fupogfakta/migrations/0007_roundconfig_started_from_scoreboard.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0.2 on 2026-03-17 08:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('fupogfakta', '0006_merge_20260315_1249'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='roundconfig',
+            name='started_from_scoreboard',
+            field=models.BooleanField(default=False),
+        ),
+    ]

fupogfakta/models.py

@@ -42,6 +42,7 @@ class GameSession(models.Model):
         LIE = "lie", "Løgnfase"
         GUESS = "guess", "Gættefase"
         REVEAL = "reveal", "Reveal"
+        SCOREBOARD = "scoreboard", "Scoreboard"
         FINISHED = "finished", "Afsluttet"
 
     host = models.ForeignKey(User, on_delete=models.PROTECT, related_name="hosted_sessions")
@@ -82,6 +83,7 @@ class RoundConfig(models.Model):
     points_bluff = models.IntegerField(default=2)
     lie_seconds = models.PositiveIntegerField(default=45)
     guess_seconds = models.PositiveIntegerField(default=30)
+    started_from_scoreboard = models.BooleanField(default=False)
 
     class Meta:
         unique_together = (("session", "number"),)

fupogfakta/payloads.py

@@ -0,0 +1,275 @@
+from datetime import timedelta
+
+from .models import GameSession, Player, RoundConfig, RoundQuestion
+
+
+def build_player_ref(player: Player | None) -> dict | None:
+    if player is None:
+        return None
+
+    return {
+        "player_id": player.id,
+        "nickname": player.nickname,
+    }
+
+
+def build_round_question_payload(round_question: RoundQuestion | None) -> dict | None:
+    if round_question is None:
+        return None
+
+    return {
+        "id": round_question.id,
+        "round_number": round_question.round_number,
+        "prompt": round_question.question.prompt,
+        "shown_at": round_question.shown_at.isoformat(),
+        "answers": [{"text": text} for text in (round_question.mixed_answers or [])],
+    }
+
+
+def build_reveal_payload(round_question: RoundQuestion | None) -> dict | None:
+    if round_question is None:
+        return None
+
+    lies = [
+        {
+            **build_player_ref(lie.player),
+            "text": lie.text,
+            "created_at": lie.created_at.isoformat(),
+        }
+        for lie in round_question.lies.select_related("player").order_by("created_at", "id")
+    ]
+
+    guesses = []
+    for guess in round_question.guesses.select_related("player", "fooled_player").order_by("created_at", "id"):
+        guess_payload = {
+            **build_player_ref(guess.player),
+            "selected_text": guess.selected_text,
+            "is_correct": guess.is_correct,
+            "created_at": guess.created_at.isoformat(),
+            "fooled_player_id": guess.fooled_player_id,
+        }
+        if guess.fooled_player is not None:
+            guess_payload["fooled_player_nickname"] = guess.fooled_player.nickname
+        guesses.append(guess_payload)
+
+    return {
+        "round_question_id": round_question.id,
+        "round_number": round_question.round_number,
+        "prompt": round_question.question.prompt,
+        "correct_answer": round_question.correct_answer,
+        "lies": lies,
+        "guesses": guesses,
+    }
+
+
+def build_leaderboard(session: GameSession) -> list[dict]:
+    return list(
+        Player.objects.filter(session=session)
+        .order_by("-score", "nickname")
+        .values("id", "nickname", "score")
+    )
+
+
+def build_lie_started_payload(session: GameSession, round_config: RoundConfig, round_question: RoundQuestion) -> dict:
+    lie_deadline_at = round_question.shown_at + timedelta(seconds=round_config.lie_seconds)
+    return {
+        "round_number": session.current_round,
+        "category": {"slug": round_config.category.slug, "name": round_config.category.name},
+        "round_question_id": round_question.id,
+        "prompt": round_question.question.prompt,
+        "shown_at": round_question.shown_at.isoformat(),
+        "lie_deadline_at": lie_deadline_at.isoformat(),
+        "lie_seconds": round_config.lie_seconds,
+    }
+
+
+def build_phase_view_model(session: GameSession, *, players_count: int, has_round_question: bool) -> dict:
+    status = session.status
+    in_lobby = status == GameSession.Status.LOBBY
+    in_lie = status == GameSession.Status.LIE
+    in_guess = status == GameSession.Status.GUESS
+    in_scoreboard = status == GameSession.Status.SCOREBOARD
+    in_finished = status == GameSession.Status.FINISHED
+
+    min_players_reached = players_count >= 3
+    max_players_allowed = players_count <= 5
+
+    return {
+        "status": status,
+        "current_phase": status,
+        "round_number": session.current_round,
+        "players_count": players_count,
+        "constraints": {
+            "min_players_to_start": 3,
+            "max_players_mvp": 5,
+            "min_players_reached": min_players_reached,
+            "max_players_allowed": max_players_allowed,
+        },
+        "readiness": {
+            "question_ready": has_round_question,
+            "scoreboard_ready": status in {GameSession.Status.REVEAL, GameSession.Status.SCOREBOARD, GameSession.Status.FINISHED},
+            "can_advance_to_next_round": in_scoreboard,
+        },
+        "host": {
+            "can_start_round": in_lobby and min_players_reached and max_players_allowed,
+            "can_show_question": False,
+            "can_mix_answers": False,
+            "can_calculate_scores": False,
+            "can_reveal_scoreboard": False,
+            "can_start_next_round": in_scoreboard,
+            "can_finish_game": in_scoreboard,
+        },
+        "player": {
+            "can_join": status in {
+                GameSession.Status.LOBBY,
+                GameSession.Status.LIE,
+                GameSession.Status.GUESS,
+                GameSession.Status.REVEAL,
+                GameSession.Status.SCOREBOARD,
+            },
+            "can_submit_lie": in_lie and has_round_question,
+            "can_submit_guess": in_guess and has_round_question,
+            "can_view_final_result": in_finished,
+        },
+    }
+
+
+def build_session_detail_gameplay_payload(
+    session: GameSession,
+    *,
+    current_round_question: RoundQuestion | None,
+    players_count: int,
+) -> dict:
+    return {
+        "round_question": build_round_question_payload(current_round_question),
+        "reveal": build_reveal_payload(current_round_question)
+        if session.status in {GameSession.Status.REVEAL, GameSession.Status.SCOREBOARD} and current_round_question
+        else None,
+        "scoreboard": build_scoreboard_phase_event(session)["payload"]["leaderboard"]
+        if session.status in {GameSession.Status.SCOREBOARD, GameSession.Status.FINISHED}
+        else None,
+        "phase_view_model": build_phase_view_model(
+            session,
+            players_count=players_count,
+            has_round_question=bool(current_round_question),
+        ),
+    }
+
+
+def build_start_round_response(
+    session: GameSession,
+    round_config: RoundConfig,
+    round_question: RoundQuestion,
+) -> dict:
+    lie_started_payload = build_lie_started_payload(session, round_config, round_question)
+    return {
+        "session": {
+            "code": session.code,
+            "status": session.status,
+            "current_round": session.current_round,
+        },
+        "round": {
+            "number": round_config.number,
+            "category": {
+                "slug": round_config.category.slug,
+                "name": round_config.category.name,
+            },
+        },
+        "round_question": {
+            "id": round_question.id,
+            "prompt": round_question.question.prompt,
+            "round_number": round_question.round_number,
+            "shown_at": round_question.shown_at.isoformat(),
+            "lie_deadline_at": lie_started_payload["lie_deadline_at"],
+        },
+        "config": {
+            "lie_seconds": round_config.lie_seconds,
+        },
+    }
+
+
+def build_question_shown_payload(round_question: RoundQuestion, lie_deadline_at: str, lie_seconds: int) -> dict:
+    return {
+        "round_question_id": round_question.id,
+        "prompt": round_question.question.prompt,
+        "shown_at": round_question.shown_at.isoformat(),
+        "lie_deadline_at": lie_deadline_at,
+        "lie_seconds": lie_seconds,
+    }
+
+
+def build_question_shown_response(round_question: RoundQuestion, lie_deadline_at: str, lie_seconds: int) -> dict:
+    return {
+        "round_question": {
+            "id": round_question.id,
+            "prompt": round_question.question.prompt,
+            "round_number": round_question.round_number,
+            "shown_at": round_question.shown_at.isoformat(),
+            "lie_deadline_at": lie_deadline_at,
+        },
+        "config": {
+            "lie_seconds": lie_seconds,
+        },
+    }
+
+
+def build_start_next_round_response(
+    session: GameSession,
+    round_config: RoundConfig,
+    round_question: RoundQuestion,
+) -> dict:
+    return build_start_round_response(session, round_config, round_question)
+
+
+def build_start_next_round_phase_event(
+    session: GameSession,
+    round_config: RoundConfig,
+    round_question: RoundQuestion,
+) -> dict:
+    return {
+        "name": "phase.lie_started",
+        "payload": build_lie_started_payload(session, round_config, round_question),
+    }
+
+
+def build_scoreboard_phase_event(session: GameSession, leaderboard: list[dict] | None = None) -> dict:
+    return {
+        "name": "phase.scoreboard",
+        "payload": {
+            "leaderboard": leaderboard if leaderboard is not None else build_leaderboard(session),
+            "current_round": session.current_round,
+        },
+    }
+
+
+def build_reveal_scoreboard_response(session: GameSession, leaderboard: list[dict]) -> dict:
+    return {
+        "session": {
+            "code": session.code,
+            "status": session.status,
+            "current_round": session.current_round,
+        },
+        "leaderboard": leaderboard,
+    }
+
+
+def build_finish_game_phase_event(session: GameSession) -> dict:
+    leaderboard = build_leaderboard(session)
+    winner = leaderboard[0] if leaderboard else None
+    return {
+        "name": "phase.game_over",
+        "payload": {"winner": winner, "leaderboard": leaderboard},
+    }
+
+
+def build_finish_game_response(session: GameSession) -> dict:
+    finish_event = build_finish_game_phase_event(session)
+    return {
+        "session": {
+            "code": session.code,
+            "status": GameSession.Status.FINISHED,
+            "current_round": session.current_round,
+        },
+        "winner": finish_event["payload"]["winner"],
+        "leaderboard": finish_event["payload"]["leaderboard"],
+    }

fupogfakta/services.py

@@ -0,0 +1,479 @@
+import random
+from datetime import timedelta
+from dataclasses import dataclass
+from typing import Any
+
+from django.db import transaction
+from django.utils import timezone
+
+from .models import Category, GameSession, Guess, LieAnswer, Player, Question, RoundConfig, RoundQuestion, ScoreEvent
+from .payloads import (
+    build_finish_game_phase_event,
+    build_finish_game_response,
+    build_lie_started_payload,
+    build_question_shown_payload,
+    build_question_shown_response,
+    build_reveal_scoreboard_response,
+    build_scoreboard_phase_event,
+    build_start_next_round_phase_event,
+    build_start_next_round_response,
+    build_start_round_response,
+)
+
+
+@dataclass(frozen=True)
+class RoundTransitionResult:
+    session: GameSession
+    round_config: RoundConfig
+    round_question: RoundQuestion
+    should_broadcast: bool
+    response_payload: dict[str, Any]
+    phase_event_name: str | None = None
+    phase_event_payload: dict[str, Any] | None = None
+
+
+@dataclass(frozen=True)
+class FinishGameResult:
+    session: GameSession
+    should_broadcast: bool
+    response_payload: dict[str, Any]
+    phase_event_name: str | None = None
+    phase_event_payload: dict[str, Any] | None = None
+
+
+@dataclass(frozen=True)
+class ScoreboardTransitionResult:
+    session: GameSession
+    leaderboard: list[dict]
+    should_broadcast: bool
+    response_payload: dict[str, Any] | None = None
+    phase_event_name: str | None = None
+    phase_event_payload: dict[str, Any] | None = None
+
+
+def get_round_question(session: GameSession, round_number: int) -> RoundQuestion | None:
+    return (
+        RoundQuestion.objects.filter(session=session, round_number=round_number)
+        .select_related("question")
+        .order_by("-id")
+        .first()
+    )
+
+
+
+def get_current_round_question(session: GameSession) -> RoundQuestion | None:
+    return get_round_question(session, session.current_round)
+
+
+
+def reset_round_question_bootstrap_state(round_question: RoundQuestion) -> RoundQuestion:
+    Guess.objects.filter(round_question=round_question).delete()
+    LieAnswer.objects.filter(round_question=round_question).delete()
+
+    update_fields: list[str] = []
+    if round_question.mixed_answers:
+        round_question.mixed_answers = []
+        update_fields.append("mixed_answers")
+
+    round_question.shown_at = timezone.now()
+    update_fields.append("shown_at")
+
+    round_question.save(update_fields=update_fields)
+    return round_question
+
+
+
+def select_round_question(
+    session: GameSession,
+    round_config: RoundConfig,
+    *,
+    round_number: int | None = None,
+) -> RoundQuestion:
+    target_round_number = session.current_round if round_number is None else round_number
+    existing_round_question = get_round_question(session, target_round_number)
+    if existing_round_question is not None and existing_round_question.question.category_id == round_config.category_id:
+        return existing_round_question
+
+    used_question_ids = RoundQuestion.objects.filter(session=session).values_list("question_id", flat=True)
+    available_questions = Question.objects.filter(
+        category=round_config.category,
+        is_active=True,
+    ).exclude(pk__in=used_question_ids)
+
+    if not available_questions.exists():
+        raise ValueError("no_available_questions")
+
+    question = random.choice(list(available_questions))
+    if existing_round_question is not None:
+        existing_round_question.question = question
+        existing_round_question.correct_answer = question.correct_answer
+        existing_round_question.save(update_fields=["question", "correct_answer"])
+        return existing_round_question
+
+    return RoundQuestion.objects.create(
+        session=session,
+        round_number=target_round_number,
+        question=question,
+        correct_answer=question.correct_answer,
+    )
+
+
+
+def prepare_mixed_answers(round_question: RoundQuestion) -> list[str]:
+    deduped_answers = list(round_question.mixed_answers or [])
+    if deduped_answers:
+        return deduped_answers
+
+    lie_texts = list(round_question.lies.values_list("text", flat=True))
+    seen = set()
+    for text in [round_question.correct_answer, *lie_texts]:
+        normalized = text.strip().casefold()
+        if not normalized or normalized in seen:
+            continue
+        seen.add(normalized)
+        deduped_answers.append(text.strip())
+
+    if len(deduped_answers) < 2:
+        raise ValueError("not_enough_answers_to_mix")
+
+    random.shuffle(deduped_answers)
+    round_question.mixed_answers = deduped_answers
+    round_question.save(update_fields=["mixed_answers"])
+    return deduped_answers
+
+
+
+
+
+def start_round(session: GameSession, category_slug: str) -> RoundTransitionResult:
+    try:
+        category = Category.objects.get(slug=category_slug, is_active=True)
+    except Category.DoesNotExist:
+        raise ValueError("category_not_found")
+
+    if not Question.objects.filter(category=category, is_active=True).exists():
+        raise ValueError("category_has_no_questions")
+
+    with transaction.atomic():
+        locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
+        if locked_session.status != GameSession.Status.LOBBY:
+            raise ValueError("round_start_invalid_phase")
+
+        if RoundConfig.objects.filter(session=locked_session, number=locked_session.current_round).exists():
+            raise ValueError("round_already_configured")
+
+        round_config = RoundConfig(
+            session=locked_session,
+            number=locked_session.current_round,
+            category=category,
+        )
+
+        round_question = select_round_question(locked_session, round_config)
+
+        round_config.save()
+        locked_session.status = GameSession.Status.LIE
+        locked_session.save(update_fields=["status"])
+
+    phase_event = {
+        "name": "phase.lie_started",
+        "payload": build_lie_started_payload(locked_session, round_config, round_question),
+    }
+    return RoundTransitionResult(
+        session=locked_session,
+        round_config=round_config,
+        round_question=round_question,
+        should_broadcast=True,
+        response_payload=build_start_round_response(locked_session, round_config, round_question),
+        phase_event_name=phase_event["name"],
+        phase_event_payload=phase_event["payload"],
+    )
+
+
+def show_question(session: GameSession) -> RoundTransitionResult:
+    if session.status != GameSession.Status.LIE:
+        raise ValueError("show_question_invalid_phase")
+
+    try:
+        round_config = RoundConfig.objects.get(session=session, number=session.current_round)
+    except RoundConfig.DoesNotExist:
+        raise ValueError("round_config_missing")
+
+    round_question = get_current_round_question(session)
+    if round_question is None:
+        round_question = select_round_question(session, round_config)
+
+    lie_deadline_at = round_question.shown_at + timedelta(seconds=round_config.lie_seconds)
+    lie_deadline_iso = lie_deadline_at.isoformat()
+    phase_event = {
+        "name": "phase.question_shown",
+        "payload": build_question_shown_payload(round_question, lie_deadline_iso, round_config.lie_seconds),
+    }
+    return RoundTransitionResult(
+        session=session,
+        round_config=round_config,
+        round_question=round_question,
+        should_broadcast=True,
+        response_payload=build_question_shown_response(round_question, lie_deadline_iso, round_config.lie_seconds),
+        phase_event_name=phase_event["name"],
+        phase_event_payload=phase_event["payload"],
+    )
+
+def start_next_round(session: GameSession) -> RoundTransitionResult:
+    with transaction.atomic():
+        locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
+        next_round_config = None
+        round_question = None
+        should_broadcast = False
+
+        phase_event_name = None
+        phase_event_payload = None
+
+        if locked_session.status == GameSession.Status.SCOREBOARD:
+            previous_round_config = RoundConfig.objects.filter(
+                session=locked_session,
+                number=locked_session.current_round,
+            ).select_related("category").first()
+            if previous_round_config is None:
+                raise ValueError("round_config_missing")
+
+            next_round_number = locked_session.current_round + 1
+            next_round_config, _created = RoundConfig.objects.get_or_create(
+                session=locked_session,
+                number=next_round_number,
+                defaults={
+                    "category": previous_round_config.category,
+                    "lie_seconds": previous_round_config.lie_seconds,
+                    "guess_seconds": previous_round_config.guess_seconds,
+                    "points_correct": previous_round_config.points_correct,
+                    "points_bluff": previous_round_config.points_bluff,
+                    "started_from_scoreboard": True,
+                },
+            )
+            round_config_update_fields: list[str] = []
+            if next_round_config.category_id != previous_round_config.category_id:
+                next_round_config.category = previous_round_config.category
+                round_config_update_fields.append("category")
+            if next_round_config.lie_seconds != previous_round_config.lie_seconds:
+                next_round_config.lie_seconds = previous_round_config.lie_seconds
+                round_config_update_fields.append("lie_seconds")
+            if next_round_config.guess_seconds != previous_round_config.guess_seconds:
+                next_round_config.guess_seconds = previous_round_config.guess_seconds
+                round_config_update_fields.append("guess_seconds")
+            if next_round_config.points_correct != previous_round_config.points_correct:
+                next_round_config.points_correct = previous_round_config.points_correct
+                round_config_update_fields.append("points_correct")
+            if next_round_config.points_bluff != previous_round_config.points_bluff:
+                next_round_config.points_bluff = previous_round_config.points_bluff
+                round_config_update_fields.append("points_bluff")
+            if not next_round_config.started_from_scoreboard:
+                next_round_config.started_from_scoreboard = True
+                round_config_update_fields.append("started_from_scoreboard")
+            if round_config_update_fields:
+                next_round_config.save(update_fields=round_config_update_fields)
+
+            locked_session.current_round = next_round_number
+
+            round_question = reset_round_question_bootstrap_state(
+                select_round_question(locked_session, next_round_config, round_number=next_round_number)
+            )
+
+            locked_session.status = GameSession.Status.LIE
+            locked_session.save(update_fields=["current_round", "status"])
+            should_broadcast = True
+            phase_event = build_start_next_round_phase_event(locked_session, next_round_config, round_question)
+            phase_event_name = phase_event["name"]
+            phase_event_payload = phase_event["payload"]
+        elif locked_session.status == GameSession.Status.LIE:
+            if locked_session.current_round <= 1:
+                raise ValueError("next_round_invalid_phase")
+
+            next_round_config = RoundConfig.objects.filter(
+                session=locked_session,
+                number=locked_session.current_round,
+            ).select_related("category").first()
+            round_question = get_current_round_question(locked_session)
+            if (
+                next_round_config is None
+                or not next_round_config.started_from_scoreboard
+                or round_question is None
+            ):
+                raise ValueError("next_round_invalid_phase")
+        else:
+            raise ValueError("next_round_invalid_phase")
+
+        return RoundTransitionResult(
+            session=locked_session,
+            round_config=next_round_config,
+            round_question=round_question,
+            should_broadcast=should_broadcast,
+            response_payload=build_start_next_round_response(
+                locked_session,
+                next_round_config,
+                round_question,
+            ),
+            phase_event_name=phase_event_name,
+            phase_event_payload=phase_event_payload,
+        )
+
+
+
+def finish_game(session: GameSession) -> FinishGameResult:
+    with transaction.atomic():
+        locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
+        should_broadcast = False
+        phase_event_name = None
+        phase_event_payload = None
+
+        if locked_session.status == GameSession.Status.SCOREBOARD:
+            locked_session.status = GameSession.Status.FINISHED
+            locked_session.save(update_fields=["status"])
+            should_broadcast = True
+            phase_event = build_finish_game_phase_event(locked_session)
+            phase_event_name = phase_event["name"]
+            phase_event_payload = phase_event["payload"]
+        elif locked_session.status != GameSession.Status.FINISHED:
+            raise ValueError("finish_game_invalid_phase")
+
+        return FinishGameResult(
+            session=locked_session,
+            should_broadcast=should_broadcast,
+            response_payload=build_finish_game_response(locked_session),
+            phase_event_name=phase_event_name,
+            phase_event_payload=phase_event_payload,
+        )
+
+
+
+def promote_reveal_to_scoreboard(session: GameSession) -> ScoreboardTransitionResult:
+    if session.status != GameSession.Status.REVEAL:
+        leaderboard = list(
+            Player.objects.filter(session=session)
+            .order_by("-score", "nickname")
+            .values("id", "nickname", "score")
+        )
+        return ScoreboardTransitionResult(
+            session=session,
+            leaderboard=leaderboard,
+            should_broadcast=False,
+            response_payload=build_reveal_scoreboard_response(session, leaderboard),
+        )
+
+    current_round_question = get_current_round_question(session)
+    if current_round_question is None:
+        leaderboard = list(
+            Player.objects.filter(session=session)
+            .order_by("-score", "nickname")
+            .values("id", "nickname", "score")
+        )
+        return ScoreboardTransitionResult(
+            session=session,
+            leaderboard=leaderboard,
+            should_broadcast=False,
+            response_payload=build_reveal_scoreboard_response(session, leaderboard),
+        )
+
+    players_count = Player.objects.filter(session=session).count()
+    guess_count = Guess.objects.filter(round_question=current_round_question).count()
+    has_score_events = ScoreEvent.objects.filter(
+        session=session,
+        meta__round_question_id=current_round_question.id,
+    ).exists()
+    reveal_is_resolved = has_score_events or (players_count > 0 and guess_count >= players_count)
+    if not reveal_is_resolved:
+        leaderboard = list(
+            Player.objects.filter(session=session)
+            .order_by("-score", "nickname")
+            .values("id", "nickname", "score")
+        )
+        return ScoreboardTransitionResult(
+            session=session,
+            leaderboard=leaderboard,
+            should_broadcast=False,
+            response_payload=build_reveal_scoreboard_response(session, leaderboard),
+        )
+
+    with transaction.atomic():
+        locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
+        if locked_session.status != GameSession.Status.REVEAL:
+            scoreboard_session = locked_session
+            should_broadcast = False
+        else:
+            locked_session.status = GameSession.Status.SCOREBOARD
+            locked_session.save(update_fields=["status"])
+            scoreboard_session = locked_session
+            should_broadcast = True
+
+    leaderboard = list(
+        Player.objects.filter(session=scoreboard_session)
+        .order_by("-score", "nickname")
+        .values("id", "nickname", "score")
+    )
+    phase_event_name = None
+    phase_event_payload = None
+    if should_broadcast:
+        phase_event = build_scoreboard_phase_event(scoreboard_session, leaderboard)
+        phase_event_name = phase_event["name"]
+        phase_event_payload = phase_event["payload"]
+    return ScoreboardTransitionResult(
+        session=scoreboard_session,
+        leaderboard=leaderboard,
+        should_broadcast=should_broadcast,
+        response_payload=build_reveal_scoreboard_response(scoreboard_session, leaderboard),
+        phase_event_name=phase_event_name,
+        phase_event_payload=phase_event_payload,
+    )
+
+
+
+def resolve_scores(
+    session: GameSession,
+    round_question: RoundQuestion,
+    round_config: RoundConfig,
+) -> tuple[list[ScoreEvent], list[dict]]:
+    guesses = list(round_question.guesses.select_related("player"))
+    if not guesses:
+        raise ValueError("no_guesses_submitted")
+
+    bluff_counts: dict[int, int] = {}
+    for guess in guesses:
+        if guess.fooled_player_id:
+            bluff_counts[guess.fooled_player_id] = bluff_counts.get(guess.fooled_player_id, 0) + 1
+
+    score_events = []
+
+    for guess in guesses:
+        if guess.is_correct:
+            guess.player.score += round_config.points_correct
+            guess.player.save(update_fields=["score"])
+            score_events.append(
+                ScoreEvent(
+                    session=session,
+                    player=guess.player,
+                    delta=round_config.points_correct,
+                    reason="guess_correct",
+                    meta={"round_question_id": round_question.id, "guess_id": guess.id},
+                )
+            )
+
+    for player_id, fooled_count in bluff_counts.items():
+        delta = fooled_count * round_config.points_bluff
+        player = Player.objects.get(pk=player_id, session=session)
+        player.score += delta
+        player.save(update_fields=["score"])
+        score_events.append(
+            ScoreEvent(
+                session=session,
+                player=player,
+                delta=delta,
+                reason="bluff_success",
+                meta={"round_question_id": round_question.id, "fooled_count": fooled_count},
+            )
+        )
+
+    ScoreEvent.objects.bulk_create(score_events)
+    leaderboard = list(
+        Player.objects.filter(session=session)
+        .order_by("-score", "nickname")
+        .values("id", "nickname", "score")
+    )
+    return score_events, leaderboard

fupogfakta/tests.py

@@ -1,2 +1,410 @@
+from datetime import timedelta
+from unittest.mock import patch
 
-# Create your tests here.
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.utils import timezone
+
+from fupogfakta.models import Category, GameSession, Guess, LieAnswer, Player, Question, RoundConfig, RoundQuestion, ScoreEvent
+from fupogfakta.payloads import (
+    build_lie_started_payload,
+    build_phase_view_model,
+    build_reveal_payload,
+    build_round_question_payload,
+    build_session_detail_gameplay_payload,
+)
+from fupogfakta.services import (
+    finish_game,
+    get_current_round_question,
+    prepare_mixed_answers,
+    promote_reveal_to_scoreboard,
+    resolve_scores,
+    select_round_question,
+    start_next_round,
+)
+
+User = get_user_model()
+
+
+class FupOgFaktaExtractionSliceTests(TestCase):
+    def setUp(self):
+        self.host = User.objects.create_user(username="host", password="secret123")
+        self.session = GameSession.objects.create(host=self.host, code="ABCD23")
+        self.category = Category.objects.create(name="Historie", slug="historie", is_active=True)
+        self.question_one = Question.objects.create(
+            category=self.category,
+            prompt="Hvornår faldt muren?",
+            correct_answer="1989",
+            is_active=True,
+        )
+        self.question_two = Question.objects.create(
+            category=self.category,
+            prompt="Hvornår kom euroen?",
+            correct_answer="1999",
+            is_active=True,
+        )
+        self.round_config = RoundConfig.objects.create(session=self.session, number=1, category=self.category)
+        self.alice = Player.objects.create(session=self.session, nickname="Alice")
+        self.bob = Player.objects.create(session=self.session, nickname="Bob")
+        self.clara = Player.objects.create(session=self.session, nickname="Clara")
+
+    def test_select_round_question_skips_already_used_questions_for_session(self):
+        RoundQuestion.objects.create(
+            session=self.session,
+            round_number=99,
+            question=self.question_one,
+            correct_answer=self.question_one.correct_answer,
+        )
+
+        round_question = select_round_question(self.session, self.round_config)
+
+        self.assertEqual(round_question.question, self.question_two)
+        self.assertEqual(get_current_round_question(self.session), round_question)
+
+    def test_prepare_mixed_answers_dedupes_blank_and_case_variants(self):
+        round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer="1989",
+        )
+        LieAnswer.objects.create(round_question=round_question, player=self.alice, text=" 1989 ")
+        LieAnswer.objects.create(round_question=round_question, player=self.bob, text="Nitten niogfirs")
+        LieAnswer.objects.create(round_question=round_question, player=self.clara, text="   ")
+
+        with patch("fupogfakta.services.random.shuffle", side_effect=lambda answers: None):
+            answers = prepare_mixed_answers(round_question)
+
+        self.assertEqual(answers, ["1989", "Nitten niogfirs"])
+        round_question.refresh_from_db()
+        self.assertEqual(round_question.mixed_answers, answers)
+
+    def test_start_next_round_moves_scoreboard_transition_into_service(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+
+        result = start_next_round(self.session)
+
+        self.session.refresh_from_db()
+        self.assertTrue(result.should_broadcast)
+        self.assertEqual(result.session.status, GameSession.Status.LIE)
+        self.assertEqual(result.session.current_round, 2)
+        self.assertEqual(result.round_config.number, 2)
+        self.assertTrue(result.round_config.started_from_scoreboard)
+        self.assertEqual(result.round_question.round_number, 2)
+
+    def test_start_next_round_rejects_plain_lie_without_scoreboard_marker(self):
+        self.session.status = GameSession.Status.LIE
+        self.session.current_round = 2
+        self.session.save(update_fields=["status", "current_round"])
+        RoundConfig.objects.create(session=self.session, number=2, category=self.category, started_from_scoreboard=False)
+        RoundQuestion.objects.create(
+            session=self.session,
+            round_number=2,
+            question=self.question_two,
+            correct_answer=self.question_two.correct_answer,
+        )
+
+        with self.assertRaisesMessage(ValueError, "next_round_invalid_phase"):
+            start_next_round(self.session)
+
+    def test_start_next_round_refreshes_shown_at_for_reused_bootstrap_question(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+        stale_shown_at = timezone.now() - timedelta(minutes=10)
+        stale_round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=2,
+            question=self.question_two,
+            correct_answer=self.question_two.correct_answer,
+            shown_at=stale_shown_at,
+            mixed_answers=["Stale truth", "Stale lie"],
+        )
+        LieAnswer.objects.create(round_question=stale_round_question, player=self.alice, text="Stale lie")
+        Guess.objects.create(
+            round_question=stale_round_question,
+            player=self.bob,
+            selected_text="Stale truth",
+            is_correct=True,
+        )
+
+        before_transition = timezone.now()
+        result = start_next_round(self.session)
+        after_transition = timezone.now()
+
+        stale_round_question.refresh_from_db()
+        self.assertEqual(result.round_question.id, stale_round_question.id)
+        self.assertGreaterEqual(stale_round_question.shown_at, before_transition)
+        self.assertLessEqual(stale_round_question.shown_at, after_transition)
+        self.assertNotEqual(stale_round_question.shown_at, stale_shown_at)
+        self.assertEqual(result.response_payload["round_question"]["shown_at"], stale_round_question.shown_at.isoformat())
+        expected_deadline = stale_round_question.shown_at + timedelta(seconds=result.round_config.lie_seconds)
+        self.assertEqual(result.response_payload["round_question"]["lie_deadline_at"], expected_deadline.isoformat())
+        self.assertGreater(expected_deadline, before_transition)
+        self.assertEqual(stale_round_question.mixed_answers, [])
+        self.assertEqual(stale_round_question.lies.count(), 0)
+        self.assertEqual(stale_round_question.guesses.count(), 0)
+
+    def test_start_next_round_reuses_existing_bootstrap_round_config_with_fresh_canonical_values(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+        stale_category = Category.objects.create(name="Sport", slug="sport", is_active=True)
+        stale_round_config = RoundConfig.objects.create(
+            session=self.session,
+            number=2,
+            category=stale_category,
+            lie_seconds=12,
+            guess_seconds=18,
+            points_correct=9,
+            points_bluff=7,
+            started_from_scoreboard=False,
+        )
+        stale_round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=2,
+            question=self.question_two,
+            correct_answer=self.question_two.correct_answer,
+            shown_at=timezone.now() - timedelta(minutes=10),
+            mixed_answers=["Stale truth"],
+        )
+
+        result = start_next_round(self.session)
+
+        stale_round_config.refresh_from_db()
+        stale_round_question.refresh_from_db()
+        self.assertEqual(result.round_config.id, stale_round_config.id)
+        self.assertEqual(RoundConfig.objects.filter(session=self.session, number=2).count(), 1)
+        self.assertEqual(stale_round_config.category_id, self.round_config.category_id)
+        self.assertEqual(stale_round_config.lie_seconds, self.round_config.lie_seconds)
+        self.assertEqual(stale_round_config.guess_seconds, self.round_config.guess_seconds)
+        self.assertEqual(stale_round_config.points_correct, self.round_config.points_correct)
+        self.assertEqual(stale_round_config.points_bluff, self.round_config.points_bluff)
+        self.assertTrue(stale_round_config.started_from_scoreboard)
+        self.assertEqual(result.round_question.id, stale_round_question.id)
+        self.assertEqual(stale_round_question.mixed_answers, [])
+
+    def test_start_next_round_repairs_reused_bootstrap_question_when_category_drifted(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+        RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer=self.question_one.correct_answer,
+        )
+        stale_category = Category.objects.create(name="Sport drift", slug="sport-drift", is_active=True)
+        stale_question = Question.objects.create(
+            category=stale_category,
+            prompt="Hvem vandt EM i 1992?",
+            correct_answer="Danmark",
+            is_active=True,
+        )
+        stale_round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=2,
+            question=stale_question,
+            correct_answer=stale_question.correct_answer,
+            shown_at=timezone.now() - timedelta(minutes=10),
+            mixed_answers=["Stale truth", "Stale lie"],
+        )
+        LieAnswer.objects.create(round_question=stale_round_question, player=self.alice, text="Tyskland")
+        Guess.objects.create(
+            round_question=stale_round_question,
+            player=self.bob,
+            selected_text="Stale truth",
+            is_correct=True,
+        )
+
+        result = start_next_round(self.session)
+
+        stale_round_question.refresh_from_db()
+        self.assertEqual(result.round_question.id, stale_round_question.id)
+        self.assertEqual(stale_round_question.question.category_id, self.round_config.category_id)
+        self.assertEqual(stale_round_question.question_id, self.question_two.id)
+        self.assertEqual(stale_round_question.correct_answer, self.question_two.correct_answer)
+        self.assertEqual(stale_round_question.mixed_answers, [])
+        self.assertEqual(stale_round_question.lies.count(), 0)
+        self.assertEqual(stale_round_question.guesses.count(), 0)
+
+    def test_start_next_round_does_not_reuse_previous_round_question_when_category_matches(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+        previous_round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer=self.question_one.correct_answer,
+            mixed_answers=["1989", "1991"],
+        )
+        LieAnswer.objects.create(round_question=previous_round_question, player=self.alice, text="1991")
+        Guess.objects.create(
+            round_question=previous_round_question,
+            player=self.bob,
+            selected_text="1991",
+            is_correct=False,
+            fooled_player=self.alice,
+        )
+
+        result = start_next_round(self.session)
+
+        previous_round_question.refresh_from_db()
+        self.session.refresh_from_db()
+        self.assertEqual(self.session.current_round, 2)
+        self.assertEqual(result.round_question.round_number, 2)
+        self.assertNotEqual(result.round_question.id, previous_round_question.id)
+        self.assertEqual(result.round_question.question_id, self.question_two.id)
+        self.assertEqual(previous_round_question.round_number, 1)
+        self.assertEqual(previous_round_question.question_id, self.question_one.id)
+        self.assertEqual(previous_round_question.mixed_answers, ["1989", "1991"])
+        self.assertEqual(previous_round_question.lies.count(), 1)
+        self.assertEqual(previous_round_question.guesses.count(), 1)
+
+    def test_finish_game_moves_scoreboard_transition_into_service(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+
+        result = finish_game(self.session)
+
+        self.session.refresh_from_db()
+        self.assertTrue(result.should_broadcast)
+        self.assertEqual(result.session.status, GameSession.Status.FINISHED)
+        self.assertEqual(self.session.status, GameSession.Status.FINISHED)
+
+    def test_promote_reveal_to_scoreboard_moves_transition_into_service(self):
+        round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer=self.question_one.correct_answer,
+        )
+        self.session.status = GameSession.Status.REVEAL
+        self.session.save(update_fields=["status"])
+
+        LieAnswer.objects.create(round_question=round_question, player=self.alice, text="Elbil")
+        Guess.objects.create(
+            round_question=round_question,
+            player=self.bob,
+            selected_text="Elbil",
+            is_correct=False,
+            fooled_player=self.alice,
+        )
+        ScoreEvent.objects.create(
+            session=self.session,
+            player=self.alice,
+            delta=5,
+            reason="bluff_success",
+            meta={"round_question_id": round_question.id},
+        )
+        self.alice.score = 5
+        self.alice.save(update_fields=["score"])
+
+        result = promote_reveal_to_scoreboard(self.session)
+
+        self.session.refresh_from_db()
+        self.assertTrue(result.should_broadcast)
+        self.assertEqual(result.session.status, GameSession.Status.SCOREBOARD)
+        self.assertEqual(result.leaderboard[0]["nickname"], self.alice.nickname)
+
+    def test_resolve_scores_applies_correct_and_bluff_points(self):
+        round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer="1989",
+        )
+        Guess.objects.create(
+            round_question=round_question,
+            player=self.alice,
+            selected_text="1989",
+            is_correct=True,
+        )
+        Guess.objects.create(
+            round_question=round_question,
+            player=self.bob,
+            selected_text="Berlin",
+            is_correct=False,
+            fooled_player=self.clara,
+        )
+        Guess.objects.create(
+            round_question=round_question,
+            player=self.clara,
+            selected_text="Berlin",
+            is_correct=False,
+            fooled_player=self.clara,
+        )
+
+        score_events, leaderboard = resolve_scores(self.session, round_question, self.round_config)
+
+        self.assertEqual(len(score_events), 2)
+        self.alice.refresh_from_db()
+        self.clara.refresh_from_db()
+        self.assertEqual(self.alice.score, self.round_config.points_correct)
+        self.assertEqual(self.clara.score, self.round_config.points_bluff * 2)
+        self.assertEqual(ScoreEvent.objects.filter(session=self.session, meta__round_question_id=round_question.id).count(), 2)
+        self.assertEqual([entry["nickname"] for entry in leaderboard], ["Alice", "Clara", "Bob"])
+
+    def test_payload_builders_expose_fupogfakta_round_contract(self):
+        round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer="1989",
+        )
+        lie = LieAnswer.objects.create(round_question=round_question, player=self.bob, text="1991")
+        Guess.objects.create(
+            round_question=round_question,
+            player=self.alice,
+            selected_text="1991",
+            is_correct=False,
+            fooled_player=self.bob,
+        )
+
+        round_question_payload = build_round_question_payload(round_question)
+        lie_payload = build_lie_started_payload(self.session, self.round_config, round_question)
+        reveal_payload = build_reveal_payload(round_question)
+        phase_view_model = build_phase_view_model(
+            self.session,
+            players_count=3,
+            has_round_question=True,
+        )
+
+        self.assertEqual(round_question_payload["prompt"], self.question_one.prompt)
+        self.assertEqual(round_question_payload["answers"], [])
+        self.assertEqual(lie_payload["category"], {"slug": self.category.slug, "name": self.category.name})
+        self.assertEqual(lie_payload["round_question_id"], round_question.id)
+        self.assertEqual(reveal_payload["correct_answer"], "1989")
+        self.assertEqual(reveal_payload["lies"][0]["player_id"], lie.player_id)
+        self.assertEqual(reveal_payload["guesses"][0]["fooled_player_nickname"], self.bob.nickname)
+        self.assertTrue(phase_view_model["host"]["can_start_round"])
+        self.assertFalse(phase_view_model["host"]["can_finish_game"])
+
+    def test_build_session_detail_gameplay_payload_keeps_session_detail_semantics_in_cartridge(self):
+        self.session.status = GameSession.Status.SCOREBOARD
+        self.session.save(update_fields=["status"])
+        round_question = RoundQuestion.objects.create(
+            session=self.session,
+            round_number=1,
+            question=self.question_one,
+            correct_answer=self.question_one.correct_answer,
+        )
+        lie = LieAnswer.objects.create(round_question=round_question, player=self.bob, text="1991")
+        Guess.objects.create(
+            round_question=round_question,
+            player=self.alice,
+            selected_text="1991",
+            is_correct=False,
+            fooled_player=self.bob,
+        )
+
+        gameplay_payload = build_session_detail_gameplay_payload(
+            self.session,
+            current_round_question=round_question,
+            players_count=3,
+        )
+
+        self.assertEqual(gameplay_payload["round_question"]["id"], round_question.id)
+        self.assertEqual(gameplay_payload["reveal"]["lies"][0]["player_id"], lie.player_id)
+        self.assertEqual(gameplay_payload["scoreboard"], [{"id": self.alice.id, "nickname": self.alice.nickname, "score": self.alice.score}, {"id": self.bob.id, "nickname": self.bob.nickname, "score": self.bob.score}, {"id": self.clara.id, "nickname": self.clara.nickname, "score": self.clara.score}])
+        self.assertEqual(gameplay_payload["phase_view_model"]["status"], GameSession.Status.SCOREBOARD)
+        self.assertTrue(gameplay_payload["phase_view_model"]["host"]["can_start_next_round"])
+        self.assertTrue(gameplay_payload["phase_view_model"]["host"]["can_finish_game"])

lobby/i18n.py

@@ -1,20 +1,100 @@
-import json
-from functools import lru_cache
-from pathlib import Path
+import logging
 
-from django.http import JsonResponse
+from django.http import HttpRequest, JsonResponse
+from django.utils.translation import get_language_from_request
+
+from partyhub.i18n_bootstrap import locale_config, shared_i18n_catalog
+
+LOGGER = logging.getLogger(__name__)
 
 
-@lru_cache(maxsize=1)
 def lobby_i18n_catalog() -> dict:
-    catalog_path = Path(__file__).resolve().parents[1] / "shared" / "i18n" / "lobby.json"
-    with catalog_path.open(encoding="utf-8") as handle:
-        return json.load(handle)
+    return shared_i18n_catalog()
+
+
+def i18n_locale_config() -> tuple[str, tuple[str, ...]]:
+    return locale_config()
 
 
 def lobby_i18n_errors() -> dict:
-    return lobby_i18n_catalog().get("backend", {}).get("error_codes", {})
+    return shared_i18n_catalog().get("backend", {}).get("error_codes", {})
 
 
-def api_error(*, code: str, message: str, status: int) -> JsonResponse:
-    return JsonResponse({"error": message, "error_code": code}, status=status)
+def lobby_i18n_error_messages() -> dict:
+    return shared_i18n_catalog().get("backend", {}).get("errors", {})
+
+
+def resolve_error_key(code: str) -> str:
+    resolved = lobby_i18n_errors().get(code)
+    if isinstance(resolved, str) and resolved:
+        return resolved
+
+    LOGGER.warning("i18n error code missing in shared catalog", extra={"code": code})
+    return code
+
+
+def _quality_value(language_candidate: str) -> float | None:
+    for parameter in language_candidate.split(";")[1:]:
+        key, separator, value = parameter.partition("=")
+        if separator and key.strip().lower() == "q":
+            try:
+                return float(value.strip())
+            except ValueError:
+                return None
+    return None
+
+
+def resolve_locale(request: HttpRequest) -> str:
+    default_locale, supported_locales = i18n_locale_config()
+
+    accept_language = request.META.get("HTTP_ACCEPT_LANGUAGE") or ""
+    ranked_candidates: list[tuple[float, int, str]] = []
+    for index, candidate in enumerate(accept_language.split(",")):
+        quality = _quality_value(candidate)
+        if quality is not None and quality <= 0:
+            continue
+
+        tag = candidate.split(";", 1)[0]
+        normalized = tag.strip().replace("_", "-").split("-", 1)[0].lower()
+        if normalized not in supported_locales:
+            continue
+
+        ranked_candidates.append((quality if quality is not None else 1.0, index, normalized))
+
+    if ranked_candidates:
+        ranked_candidates.sort(key=lambda entry: (-entry[0], entry[1]))
+        return ranked_candidates[0][2]
+
+    requested = (get_language_from_request(request) or "").replace("_", "-").split("-", 1)[0].lower()
+    if requested in supported_locales:
+        return requested
+    return default_locale
+
+
+def resolve_error_message(*, key: str, locale: str) -> str:
+    default_locale, _supported_locales = i18n_locale_config()
+    translations = lobby_i18n_error_messages().get(key)
+    if not isinstance(translations, dict):
+        LOGGER.warning("i18n key missing in shared catalog", extra={"key": key, "locale": locale})
+        return key
+
+    if locale in translations and translations[locale]:
+        return translations[locale]
+    if default_locale in translations and translations[default_locale]:
+        return translations[default_locale]
+
+    LOGGER.warning("i18n translation missing for key", extra={"key": key, "locale": locale})
+    return key
+
+
+def api_error(request: HttpRequest, *, code: str, status: int) -> JsonResponse:
+    locale = resolve_locale(request)
+    key = resolve_error_key(code)
+    return JsonResponse(
+        {
+            "error": resolve_error_message(key=key, locale=locale),
+            "error_code": code,
+            "locale": locale,
+        },
+        status=status,
+    )

lobby/management/commands/smoke_staging.py

@@ -10,7 +10,7 @@ from fupogfakta.models import Category, GameSession, Player, Question, RoundQues
 
 
 class Command(BaseCommand):
-    help = "Run minimal staging smoke flow for lobby gameplay"
+    help = "Run canonical gameplay smoke/regression flow for bluff -> guess -> reveal -> scoreboard"
 
     def add_arguments(self, parser):
         parser.add_argument(
@@ -18,6 +18,26 @@ class Command(BaseCommand):
             help="Optional path to write smoke result artifact as JSON",
         )
 
+    def _fail(self, step: str, detail: str, payload=None):
+        message = f"{step} failed: {detail}"
+        if payload is not None:
+            message += f" | payload={json.dumps(payload, sort_keys=True)}"
+        raise CommandError(message)
+
+    def _expect_status(self, response, expected_status: int, step: str):
+        if response.status_code != expected_status:
+            try:
+                payload = response.json()
+            except ValueError:
+                payload = {"raw": response.content.decode("utf-8", errors="replace")}
+            self._fail(step, f"expected HTTP {expected_status}, got {response.status_code}", payload)
+        return response.json()
+
+    def _expect_session_status(self, payload: dict, expected_status: str, step: str):
+        actual_status = payload.get("session", {}).get("status")
+        if actual_status != expected_status:
+            self._fail(step, f"expected session.status={expected_status}, got {actual_status}", payload)
+
     def handle(self, *args, **options):
         GameSession.objects.all().delete()
         Player.objects.all().delete()
@@ -30,11 +50,14 @@ class Command(BaseCommand):
         category.is_active = True
         category.save(update_fields=["is_active"])
 
-        Question.objects.get_or_create(
+        question, _ = Question.objects.get_or_create(
             category=category,
             prompt="Smoke prompt?",
             defaults={"correct_answer": "Correct", "is_active": True},
         )
+        if not question.is_active:
+            question.is_active = True
+            question.save(update_fields=["is_active"])
 
         User = get_user_model()
         host, _ = User.objects.get_or_create(username="smoke-host")
@@ -42,121 +65,254 @@ class Command(BaseCommand):
         host.is_staff = True
         host.save()
 
+        artifact = {
+            "ok": True,
+            "command": "python manage.py smoke_staging --artifact <path>",
+            "generated_at": datetime.now(timezone.utc).isoformat(),
+            "question": {
+                "prompt": question.prompt,
+                "correct_answer": question.correct_answer,
+            },
+            "steps": [],
+        }
+
         host_client = Client()
         host_client.force_login(host)
 
-        create_res = host_client.post("/lobby/sessions/create", content_type="application/json")
-        if create_res.status_code != 201:
-            raise CommandError(f"create_session failed: {create_res.status_code} {create_res.content!r}")
-
-        code = create_res.json()["session"]["code"]
+        create_payload = self._expect_status(
+            host_client.post("/lobby/sessions/create", content_type="application/json"),
+            201,
+            "create_session",
+        )
+        code = create_payload["session"]["code"]
+        artifact["session_code"] = code
+        artifact["steps"].append(
+            {
+                "step": "create_session",
+                "session_status": create_payload["session"]["status"],
+            }
+        )
 
         players = []
         for nickname in ["P1", "P2", "P3"]:
-            join_res = Client().post(
-                "/lobby/sessions/join",
-                data=json.dumps({"code": code, "nickname": nickname}),
-                content_type="application/json",
-            )
-            if join_res.status_code != 201:
-                raise CommandError(f"join_session failed for {nickname}: {join_res.status_code}")
-            players.append(join_res.json()["player"])
-
-        start_res = host_client.post(
-            f"/lobby/sessions/{code}/rounds/start",
-            data=json.dumps({"category_slug": category.slug}),
-            content_type="application/json",
-        )
-        if start_res.status_code != 201:
-            raise CommandError(f"start_round failed: {start_res.status_code}")
-
-        show_res = host_client.post(f"/lobby/sessions/{code}/questions/show", content_type="application/json")
-        if show_res.status_code != 201:
-            raise CommandError(f"show_question failed: {show_res.status_code}")
-
-        round_question_id = show_res.json()["round_question"]["id"]
-
-        for player in players:
-            nick = player["nickname"]
-            lie_res = Client().post(
-                f"/lobby/sessions/{code}/questions/{round_question_id}/lies/submit",
-                data=json.dumps(
-                    {
-                        "player_id": player["id"],
-                        "session_token": player["session_token"],
-                        "text": f"Lie from {nick}",
-                    }
+            join_payload = self._expect_status(
+                Client().post(
+                    "/lobby/sessions/join",
+                    data=json.dumps({"code": code, "nickname": nickname}),
+                    content_type="application/json",
                 ),
-                content_type="application/json",
+                201,
+                f"join_session[{nickname}]",
             )
-            if lie_res.status_code != 201:
-                raise CommandError(f"submit_lie failed for {nick}: {lie_res.status_code}")
-
-        mix_res = host_client.post(
-            f"/lobby/sessions/{code}/questions/{round_question_id}/answers/mix",
-            content_type="application/json",
+            players.append(join_payload["player"])
+        artifact["players"] = [player["nickname"] for player in players]
+        artifact["steps"].append(
+            {
+                "step": "join_players",
+                "players_count": len(players),
+            }
         )
-        if mix_res.status_code != 200:
-            raise CommandError(f"mix_answers failed: {mix_res.status_code}")
 
-        answers = mix_res.json().get("answers", [])
+        start_payload = self._expect_status(
+            host_client.post(
+                f"/lobby/sessions/{code}/rounds/start",
+                data=json.dumps({"category_slug": category.slug}),
+                content_type="application/json",
+            ),
+            201,
+            "start_round",
+        )
+        self._expect_session_status(start_payload, GameSession.Status.LIE, "start_round")
+
+        round_question_id = start_payload["round_question"]["id"]
+        artifact["round_question_id"] = round_question_id
+        artifact["steps"].append(
+            {
+                "step": "start_round",
+                "session_status": start_payload["session"]["status"],
+                "round_question_id": round_question_id,
+            }
+        )
+
+        answers = []
+        lie_transition_payload = None
+        for player in players:
+            nickname = player["nickname"]
+            lie_payload = self._expect_status(
+                Client().post(
+                    f"/lobby/sessions/{code}/questions/{round_question_id}/lies/submit",
+                    data=json.dumps(
+                        {
+                            "player_id": player["id"],
+                            "session_token": player["session_token"],
+                            "text": f"Lie from {nickname}",
+                        }
+                    ),
+                    content_type="application/json",
+                ),
+                201,
+                f"submit_lie[{nickname}]",
+            )
+            if lie_payload.get("answers"):
+                answers = lie_payload["answers"]
+                lie_transition_payload = lie_payload
+
         if not answers:
-            raise CommandError("mix_answers returned empty answers")
+            detail_payload = self._expect_status(host_client.get(f"/lobby/sessions/{code}"), 200, "session_detail_after_lies")
+            answers = detail_payload.get("round_question", {}).get("answers", [])
+            self._expect_session_status(detail_payload, GameSession.Status.GUESS, "session_detail_after_lies")
+            lie_transition_payload = detail_payload
 
-        for player in players:
-            nick = player["nickname"]
-            selected = next((a for a in answers if a.get("player_id") != player["id"]), answers[0])
-            guess_res = Client().post(
-                f"/lobby/sessions/{code}/questions/{round_question_id}/guesses/submit",
-                data=json.dumps(
-                    {
-                        "player_id": player["id"],
-                        "session_token": player["session_token"],
-                        "selected_text": selected["text"],
-                    }
-                ),
-                content_type="application/json",
+        if not answers:
+            self._fail("auto_guess_transition", "canonical lie->guess transition returned empty answers")
+
+        if not any(answer.get("text") == question.correct_answer for answer in answers):
+            self._fail("auto_guess_transition", "mixed answers missing correct answer", {"answers": answers})
+        if len(answers) < len(players) + 1:
+            self._fail(
+                "auto_guess_transition",
+                "mixed answers shorter than expected bluff set",
+                {"answers": answers, "players_count": len(players)},
             )
-            if guess_res.status_code != 201:
-                raise CommandError(f"submit_guess failed for {nick}: {guess_res.status_code}")
 
-        calc_res = host_client.post(
-            f"/lobby/sessions/{code}/questions/{round_question_id}/scores/calculate",
-            content_type="application/json",
+        self._expect_session_status(lie_transition_payload, GameSession.Status.GUESS, "auto_guess_transition")
+        artifact["steps"].append(
+            {
+                "step": "auto_guess_transition",
+                "session_status": lie_transition_payload["session"]["status"],
+                "answers": [answer["text"] for answer in answers],
+            }
         )
-        if calc_res.status_code != 200:
-            raise CommandError(f"calculate_scores failed: {calc_res.status_code}")
 
-        board_res = host_client.get(f"/lobby/sessions/{code}/scoreboard")
-        if board_res.status_code != 200:
-            raise CommandError(f"reveal_scoreboard failed: {board_res.status_code}")
+        answer_texts = {answer["text"] for answer in answers}
+        correct_answer = next((answer["text"] for answer in answers if answer.get("text") == question.correct_answer), None)
+        if correct_answer is None:
+            self._fail("submit_guesses", "could not resolve correct answer from mixed answers", {"answers": answers})
 
-        finish_res = host_client.post(f"/lobby/sessions/{code}/finish", content_type="application/json")
-        if finish_res.status_code != 200:
-            raise CommandError(f"finish_game failed: {finish_res.status_code}")
+        guess_plan = {
+            players[0]["nickname"]: "Lie from P2",
+            players[1]["nickname"]: correct_answer,
+            players[2]["nickname"]: "Lie from P1",
+        }
+        missing_guess_targets = {text for text in guess_plan.values() if text not in answer_texts}
+        if missing_guess_targets:
+            self._fail(
+                "submit_guesses",
+                "expected bluff targets missing from mixed answers",
+                {"answers": answers, "missing_guess_targets": sorted(missing_guess_targets)},
+            )
+        artifact["guess_plan"] = guess_plan
+
+        guess_payloads = []
+        for player in players:
+            nickname = player["nickname"]
+            guess_payload = self._expect_status(
+                Client().post(
+                    f"/lobby/sessions/{code}/questions/{round_question_id}/guesses/submit",
+                    data=json.dumps(
+                        {
+                            "player_id": player["id"],
+                            "session_token": player["session_token"],
+                            "selected_text": guess_plan[nickname],
+                        }
+                    ),
+                    content_type="application/json",
+                ),
+                201,
+                f"submit_guess[{nickname}]",
+            )
+            guess_payloads.append(guess_payload)
+
+        reveal_payload = guess_payloads[-1]
+        self._expect_session_status(reveal_payload, GameSession.Status.REVEAL, "auto_reveal_transition")
+        if not reveal_payload.get("phase_transition", {}).get("auto_advanced"):
+            self._fail("auto_reveal_transition", "expected auto_advanced=true on final guess", reveal_payload)
+        reveal = reveal_payload.get("reveal")
+        if not reveal:
+            self._fail("auto_reveal_transition", "missing canonical reveal payload", reveal_payload)
+        if reveal.get("correct_answer") != question.correct_answer:
+            self._fail(
+                "auto_reveal_transition",
+                "reveal payload returned wrong correct answer",
+                {"expected": question.correct_answer, "reveal": reveal},
+            )
+        if len(reveal.get("lies", [])) != len(players):
+            self._fail("auto_reveal_transition", "unexpected lie count in reveal payload", reveal)
+        if len(reveal.get("guesses", [])) != len(players):
+            self._fail("auto_reveal_transition", "unexpected guess count in reveal payload", reveal)
+
+        fooled_guesses = [guess for guess in reveal["guesses"] if not guess.get("is_correct")]
+        correct_guesses = [guess for guess in reveal["guesses"] if guess.get("is_correct")]
+        if len(fooled_guesses) != 2:
+            self._fail("auto_reveal_transition", "expected exactly two bluff guesses", reveal)
+        if len(correct_guesses) != 1:
+            self._fail("auto_reveal_transition", "expected exactly one correct guess", reveal)
+        if any(guess.get("fooled_player_id") is None for guess in fooled_guesses):
+            self._fail("auto_reveal_transition", "bluff guesses missing fooled_player_id", reveal)
+
+        artifact["steps"].append(
+            {
+                "step": "submit_guesses",
+                "guess_results": [
+                    {
+                        "player_id": payload["guess"]["player_id"],
+                        "selected_text": payload["guess"]["selected_text"],
+                        "is_correct": payload["guess"]["is_correct"],
+                        "fooled_player_id": payload["guess"].get("fooled_player_id"),
+                    }
+                    for payload in guess_payloads
+                ],
+            }
+        )
+        artifact["steps"].append(
+            {
+                "step": "auto_reveal_transition",
+                "session_status": reveal_payload["session"]["status"],
+                "reveal": {
+                    "correct_answer": reveal["correct_answer"],
+                    "lies_count": len(reveal["lies"]),
+                    "guesses_count": len(reveal["guesses"]),
+                    "fooled_player_ids": sorted(guess["fooled_player_id"] for guess in fooled_guesses),
+                    "correct_guess_player_ids": sorted(guess["player_id"] for guess in correct_guesses),
+                },
+            }
+        )
+
+        detail_payload = self._expect_status(host_client.get(f"/lobby/sessions/{code}"), 200, "session_detail_after_guesses")
+        self._expect_session_status(detail_payload, GameSession.Status.SCOREBOARD, "auto_scoreboard_transition")
+        if detail_payload.get("reveal") != reveal:
+            self._fail("auto_scoreboard_transition", "scoreboard promotion changed canonical reveal payload", detail_payload)
+        scoreboard = detail_payload.get("scoreboard")
+        if not scoreboard:
+            self._fail("auto_scoreboard_transition", "missing scoreboard payload after promotion", detail_payload)
+        if len(scoreboard) != len(players):
+            self._fail("auto_scoreboard_transition", "unexpected scoreboard length", detail_payload)
+        if not detail_payload.get("phase_view_model", {}).get("readiness", {}).get("scoreboard_ready"):
+            self._fail("auto_scoreboard_transition", "scoreboard_ready=false after promotion", detail_payload)
+
+        artifact["steps"].append(
+            {
+                "step": "auto_scoreboard_transition",
+                "session_status": detail_payload["session"]["status"],
+                "leaderboard": scoreboard,
+            }
+        )
+
+        finish_payload = self._expect_status(
+            host_client.post(f"/lobby/sessions/{code}/finish", content_type="application/json"),
+            200,
+            "finish_game",
+        )
+        self._expect_session_status(finish_payload, GameSession.Status.FINISHED, "finish_game")
+        artifact["steps"].append(
+            {
+                "step": "finish_game",
+                "session_status": finish_payload["session"]["status"],
+            }
+        )
 
         artifact_path = options.get("artifact")
         if artifact_path:
-            artifact = {
-                "ok": True,
-                "command": "smoke_staging",
-                "generated_at": datetime.now(timezone.utc).isoformat(),
-                "session_code": code,
-                "players": [player["nickname"] for player in players],
-                "round_question_id": round_question_id,
-                "steps": [
-                    "create_session",
-                    "join_players",
-                    "start_round",
-                    "show_question",
-                    "submit_lies",
-                    "mix_answers",
-                    "submit_guesses",
-                    "calculate_scores",
-                    "reveal_scoreboard",
-                    "finish_game",
-                ],
-            }
             output_path = Path(artifact_path)
             output_path.parent.mkdir(parents=True, exist_ok=True)
             output_path.write_text(json.dumps(artifact, indent=2) + "\n", encoding="utf-8")

lobby/templates/lobby/host_screen.html

@@ -24,14 +24,10 @@
 <p id="categoryGuardHint">Kategori er kun redigérbar i lobby-fasen.</p>
 
 <p id="phaseStatus">Fase: ukendt (opdatér session-status).</p>
-<button id="showQuestionBtn" onclick="showQuestion()" disabled>3) Vis spørgsmål</button>
-<input id="roundQuestionId" placeholder="Round question id">
-<p id="roundQuestionGuardHint">Round question-id kan kun redigeres i lie/guess/reveal-faser.</p>
-<button id="mixAnswersBtn" onclick="mixAnswers()" disabled>4) Mix svar</button>
-<button id="calcScoresBtn" onclick="calcScores()" disabled>5) Beregn score</button>
-<button id="showScoreboardBtn" onclick="showScoreboard()" disabled>6) Scoreboard</button>
-<button id="nextRoundBtn" onclick="nextRound()" disabled>7) Næste runde</button>
-<button id="finishGameBtn" onclick="finishGame()" disabled>8) Afslut spil</button>
+<p id="roundQuestionStatus">Aktiv round question: afventer session-status.</p>
+<p id="roundQuestionGuardHint">Round question-id styres server-side i canonical flow og er kun read-only kontekst for host.</p>
+<button id="nextRoundBtn" onclick="nextRound()" disabled>3) Næste runde</button>
+<button id="finishGameBtn" onclick="finishGame()" disabled>4) Afslut spil</button>
 <p id="hostActionHint">Angiv sessionkode for at aktivere host-actions.</p>
 <p id="hostErrorHint">Ingen fejl.</p>
 <button id="sessionDetailBtn" onclick="sessionDetail()">Session-status</button>
@@ -55,8 +51,12 @@
   <p id="hostCriticalPlayers">Spillere: afventer</p>
   <p id="hostCriticalRound">Aktiv round question: afventer</p>
 </section>
-<pre id="out">Klar.</pre>
+<pre id="out">Ready.</pre>
+{{ lobby_i18n|json_script:"wppHostI18n" }}
 <script>
+var WPP_HOST_LOCALE="{{ shell_locale|default:'en'|escapejs }}";
+var WPP_HOST_I18N=JSON.parse(document.getElementById("wppHostI18n").textContent||"{}");
+function hostCopy(path,fallback){var node=WPP_HOST_I18N;var parts=(path||"").split(".");for(var i=0;i<parts.length;i++){if(!node||typeof node!=="object"){return fallback||path;}node=node[parts[i]];}if(node&&typeof node==="object"){if(node[WPP_HOST_LOCALE]){return node[WPP_HOST_LOCALE];}if(node.en){return node.en;}}return typeof node==="string"?node:(fallback||path);} 
 var currentSessionStatus="";
 var autoRefreshEnabled=false;
 var autoRefreshTimer=null;
@@ -65,14 +65,15 @@ var lastRefreshAtLabel="";
 var lastRefreshFailed=false;
 var sessionDetailInFlight=false;
 var hostShellRouteHint="";
-var HOST_SHELL_ROUTES={lobby:"lobby",lie:"lie",guess:"guess",reveal:"reveal",finished:"finished"};
+var HOST_SHELL_ROUTES={lobby:"lobby",lie:"lie",guess:"guess",reveal:"reveal",scoreboard:"scoreboard",finished:"finished"};
 var hostShellFatalError=false;
 var hostShellRecoverInFlight=false;
 var hostCriticalHydrated=false;
 function setHostCriticalLoading(isLoading){var skeleton=document.getElementById("hostCriticalSkeleton");var view=document.getElementById("hostCriticalView");if(!skeleton||!view){return;}skeleton.style.display=isLoading?"block":"none";view.style.display=isLoading?"none":"block";}
-function hydrateHostCriticalView(data){var session=(data&&data.session)||{};var phaseEl=document.getElementById("hostCriticalPhase");var playersEl=document.getElementById("hostCriticalPlayers");var roundEl=document.getElementById("hostCriticalRound");if(phaseEl){phaseEl.textContent="Fase: "+phaseLabel(currentSessionStatus||session.status||"");}
+function hydrateHostCriticalView(data){var session=(data&&data.session)||{};var phaseEl=document.getElementById("hostCriticalPhase");var playersEl=document.getElementById("hostCriticalPlayers");var roundEl=document.getElementById("hostCriticalRound");var roundStatus=document.getElementById("roundQuestionStatus");var roundQuestionId=(data&&data.round_question&&data.round_question.id)?String(data.round_question.id):"";if(phaseEl){phaseEl.textContent="Fase: "+phaseLabel(currentSessionStatus||session.status||"");}
 if(playersEl){playersEl.textContent="Spillere: "+(typeof session.players_count==="number"?session.players_count:"ukendt");}
-if(roundEl){roundEl.textContent="Aktiv round question: "+(rq()||"ikke valgt");}
+if(roundEl){roundEl.textContent="Aktiv round question: "+(roundQuestionId||"ikke valgt");}
+if(roundStatus){roundStatus.textContent="Aktiv round question: "+(roundQuestionId||"afventer session-status.");}
 hostCriticalHydrated=true;
 setHostCriticalLoading(false);
 }
@@ -82,10 +83,9 @@ function setHostShellFatalError(detail){hostShellFatalError=true;var out=documen
 function clearHostShellFatalError(){hostShellFatalError=false;hostShellRecoverInFlight=false;updateHostShellErrorBoundary();}
 function recoverHostShell(mode){if(hostShellRecoverInFlight){return Promise.resolve({error:"recover_in_flight"});}hostShellRecoverInFlight=true;updateHostShellErrorBoundary();if(mode==="reload"){window.location.reload();return Promise.resolve({ok:true});}if(!code()){hostShellRecoverInFlight=false;updateHostShellErrorBoundary();return Promise.resolve({error:"missing_session_code"});}return sessionDetail().then(function(result){clearHostShellFatalError();return result;}).catch(function(err){hostShellRecoverInFlight=false;updateHostShellErrorBoundary();throw err;});}
 function code(){return document.getElementById("code").value.trim().toUpperCase();}
-function rq(){return document.getElementById("roundQuestionId").value.trim();}
-function saveHostContext(){try{localStorage.setItem("wppHostContext",JSON.stringify({code:code(),round_question_id:rq(),session_status:currentSessionStatus||"",auto_refresh:autoRefreshEnabled}));}catch(_e){}}
-function restoreHostContext(){try{var raw=localStorage.getItem("wppHostContext");if(!raw){return false;}var ctx=JSON.parse(raw);if(ctx.code){document.getElementById("code").value=(ctx.code||"").toUpperCase();}if(ctx.round_question_id){document.getElementById("roundQuestionId").value=ctx.round_question_id;}if(ctx.session_status){currentSessionStatus=ctx.session_status;}autoRefreshEnabled=!!ctx.auto_refresh;updateAutoRefreshUi();return !!ctx.code;}catch(_e){return false;}}
-function phaseLabel(status){if(status==="lobby"){return"Lobby";}if(status==="lie"){return"Løgn";}if(status==="guess"){return"Gæt";}if(status==="reveal"){return"Reveal";}if(status==="finished"){return"Afsluttet";}return"Ukendt";}
+function saveHostContext(){try{localStorage.setItem("wppHostContext",JSON.stringify({code:code(),session_status:currentSessionStatus||"",auto_refresh:autoRefreshEnabled}));}catch(_e){}}
+function restoreHostContext(){try{var raw=localStorage.getItem("wppHostContext");if(!raw){return false;}var ctx=JSON.parse(raw);if(ctx.code){document.getElementById("code").value=(ctx.code||"").toUpperCase();}if(ctx.session_status){currentSessionStatus=ctx.session_status;}autoRefreshEnabled=!!ctx.auto_refresh;updateAutoRefreshUi();return !!ctx.code;}catch(_e){return false;}}
+function phaseLabel(status){if(status==="lobby"){return"Lobby";}if(status==="lie"){return"Lie";}if(status==="guess"){return"Guess";}if(status==="reveal"){return"Reveal";}if(status==="scoreboard"){return"Scoreboard";}if(status==="finished"){return"Finished";}return"Unknown";}
 function hostShellRouteFromPath(){var marker="/lobby/ui/host";var path=(window.location.pathname||"").toLowerCase();var idx=path.indexOf(marker);if(idx===-1){return"";}var remainder=path.slice(idx+marker.length).replace(/^\/+|\/+$/g,"");if(!remainder){return"";}var route=remainder.split("/")[0];return HOST_SHELL_ROUTES[route]?route:"";}
 function expectedHostShellRoute(){return HOST_SHELL_ROUTES[currentSessionStatus]||"";}
 function syncHostShellRoute(){var currentRoute=hostShellRouteFromPath();var expectedRoute=expectedHostShellRoute();if(!currentRoute||!expectedRoute){hostShellRouteHint="";return;}if(currentRoute===expectedRoute){hostShellRouteHint="";return;}var nextPath="/lobby/ui/host/"+expectedRoute;window.history.replaceState(null,"",nextPath);hostShellRouteHint="Deep-link route guard: omdirigeret fra /"+currentRoute+" til /"+expectedRoute+" for fase "+phaseLabel(currentSessionStatus)+".";}
@@ -93,31 +93,27 @@ function updateAutoRefreshUi(){var btn=document.getElementById("autoRefreshToggl
 function stopAutoRefresh(reason){autoRefreshEnabled=false;if(autoRefreshTimer){clearInterval(autoRefreshTimer);autoRefreshTimer=null;}if(reason){var hint=document.getElementById("autoRefreshHint");if(hint){hint.textContent=reason;}}updateAutoRefreshUi();saveHostContext();}
 function startAutoRefresh(){if(!code()){updateAutoRefreshUi();return;}autoRefreshEnabled=true;if(autoRefreshTimer){clearInterval(autoRefreshTimer);}autoRefreshTimer=setInterval(function(){if(!code()||sessionDetailInFlight){return;}if(currentSessionStatus==="finished"){stopAutoRefresh("Auto-refresh stoppet: spillet er afsluttet.");return;}sessionDetail();},10000);updateAutoRefreshUi();saveHostContext();}
 function toggleAutoRefresh(){if(hostActionInFlight||sessionDetailInFlight||!code()){updateAutoRefreshUi();return;}if(autoRefreshEnabled){stopAutoRefresh();return;}startAutoRefresh();}
-function formatTimeLabel(dateObj){return dateObj.toLocaleTimeString("da-DK",{hour12:false});}
+function formatTimeLabel(dateObj){return dateObj.toLocaleTimeString(WPP_HOST_LOCALE,{hour12:false});}
 function markSessionRefresh(status){if(status>=200&&status<300){lastRefreshAtLabel=formatTimeLabel(new Date());lastRefreshFailed=false;}else{lastRefreshFailed=true;}updateLastRefreshStatus();}
 function updateLastRefreshStatus(){var el=document.getElementById("lastRefreshStatus");if(!el){return;}if(!lastRefreshAtLabel){el.textContent=lastRefreshFailed?"Session-data kan være forældet (ingen succesfuld opdatering endnu).":"Session-data ikke opdateret endnu.";return;}if(lastRefreshFailed){el.textContent="Session-data kan være forældet (seneste succes: "+lastRefreshAtLabel+").";return;}el.textContent="Sidst opdateret: "+lastRefreshAtLabel+".";}
 function normalizeApiError(data){if(!data||typeof data!=="object"){return"";}return (data.error_code||data.error||"").toString();}
-function mapUiErrorMessage(errorKey){if(!errorKey){return"";}var key=errorKey.toLowerCase();if(key.indexOf("phase")!==-1){return"Ugyldig fase for handlingen. Opdatér session-status og prøv igen.";}if(key.indexOf("token")!==-1||key.indexOf("auth")!==-1){return"Session-token er ugyldig eller udløbet. Rejoin sessionen og prøv igen.";}if(key.indexOf("round")!==-1||key.indexOf("question")!==-1||key.indexOf("state")!==-1){return"Runde-kontekst matcher ikke længere. Opdatér session-status før næste handling.";}if(key.indexOf("session")!==-1){return"Sessionkoden er ugyldig eller sessionen findes ikke længere.";}return"Handling fejlede. Opdatér session-status og prøv igen.";}
+function mapUiErrorMessage(errorKey){if(!errorKey){return"";}var key=errorKey.toLowerCase();if(WPP_HOST_I18N&&WPP_HOST_I18N.backend&&WPP_HOST_I18N.backend.errors&&WPP_HOST_I18N.backend.errors[key]){return hostCopy("backend.errors."+key,"Action failed. Refresh state and retry.");}if(key.indexOf("session")!==-1){return hostCopy("backend.errors.session_not_found_or_closed","Session code is invalid, or session no longer exists.");}return hostCopy("backend.errors.generic_action_failed_retry","Action failed. Refresh state and retry.");}
 function updateErrorHint(status,data){var el=document.getElementById("hostErrorHint");if(!el){return;}if(status>=200&&status<300){el.textContent="Ingen fejl.";return;}var errKey=normalizeApiError(data);el.textContent="Fejl: "+mapUiErrorMessage(errKey)+" ("+(errKey||("http_"+status))+")";}
 function updateCreateSessionState(){var btn=document.getElementById("createSessionBtn");var hint=document.getElementById("createSessionHint");if(btn){btn.disabled=hostActionInFlight||sessionDetailInFlight;}if(!hint){return;}if(hostActionInFlight){hint.textContent="Opret session er låst mens en host-handling kører.";return;}if(sessionDetailInFlight){hint.textContent="Opret session er låst mens session-opdatering kører.";return;}hint.textContent="Opret session er klar.";}function updateSessionDetailState(){var btn=document.getElementById("sessionDetailBtn");var hint=document.getElementById("sessionDetailHint");var codeInput=document.getElementById("code");if(btn){btn.disabled=sessionDetailInFlight||hostActionInFlight||!code();}if(codeInput){codeInput.readOnly=sessionDetailInFlight||hostActionInFlight;}if(!hint){return;}if(sessionDetailInFlight){hint.textContent="Opdaterer session-status…";return;}if(hostActionInFlight){hint.textContent="Session-opdatering er låst mens en host-handling kører.";return;}if(!code()){hint.textContent="Angiv sessionkode for at opdatere session-status.";updateHostShellErrorBoundary();return;}hint.textContent="Session-opdatering klar.";updateHostShellErrorBoundary();}
 
 function updatePhaseStatus(){var el=document.getElementById("phaseStatus");syncHostShellRoute();if(!el){return;}if(!currentSessionStatus){el.textContent="Fase: ukendt (opdatér session-status).";return;}el.textContent="Fase: "+phaseLabel(currentSessionStatus)+" ("+currentSessionStatus+")";}
 function syncStartRoundGuard(data){var btn=document.getElementById("startRoundBtn");var hint=document.getElementById("startRoundHint");var status=document.getElementById("playerCountStatus");if(!btn||!hint||!status){return;}var count=(data&&data.session&&typeof data.session.players_count==="number")?data.session.players_count:null;var phase=currentSessionStatus||"";if(phase&&phase!=="lobby"){btn.disabled=true;status.textContent=count===null?"Spillere i session: ukendt":"Spillere i session: "+count;hint.textContent="Start runde er kun tilladt i lobby-fasen.";return;}if(count===null){btn.disabled=true;status.textContent="Spillere i session: ukendt";hint.textContent="Opdatér session-status for at validere 3-5 spillere.";return;}status.textContent="Spillere i session: "+count;if(count<3){btn.disabled=true;hint.textContent="Mangler spillere: kræver mindst 3 for at starte runde.";return;}if(count>5){btn.disabled=true;hint.textContent="For mange spillere: maks 5 i MVP før runde-start.";return;}btn.disabled=false;hint.textContent="Klar: spillerantal er indenfor 3-5 til runde-start.";}
 
-function updateHostActionState(){updateCreateSessionState();var hasCode=!!code();var hasRound=!!rq();var phase=currentSessionStatus||"";var showQuestionBtn=document.getElementById("showQuestionBtn");var mixAnswersBtn=document.getElementById("mixAnswersBtn");var calcScoresBtn=document.getElementById("calcScoresBtn");var showScoreboardBtn=document.getElementById("showScoreboardBtn");var nextRoundBtn=document.getElementById("nextRoundBtn");var finishGameBtn=document.getElementById("finishGameBtn");var roundQuestionInput=document.getElementById("roundQuestionId");var roundQuestionGuardHint=document.getElementById("roundQuestionGuardHint");var categorySelect=document.getElementById("category");var categoryGuardHint=document.getElementById("categoryGuardHint");var hint=document.getElementById("hostActionHint");if(showQuestionBtn){showQuestionBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="lie";}if(showScoreboardBtn){showScoreboardBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="reveal";}if(nextRoundBtn){nextRoundBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="reveal";}if(finishGameBtn){finishGameBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="reveal";}if(mixAnswersBtn){mixAnswersBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||!hasRound||(phase!=="lie"&&phase!=="guess");}if(calcScoresBtn){calcScoresBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||!hasRound||phase!=="guess";}var canEditRoundQuestion=!!hasCode&&(phase==="lie"||phase==="guess"||phase==="reveal");if(roundQuestionInput){roundQuestionInput.disabled=hostActionInFlight||sessionDetailInFlight||!canEditRoundQuestion;}if(roundQuestionGuardHint){if(hostActionInFlight){roundQuestionGuardHint.textContent="Round question-id er låst mens en handling kører.";}else if(sessionDetailInFlight){roundQuestionGuardHint.textContent="Round question-id er låst mens session-opdatering kører.";}else if(!hasCode){roundQuestionGuardHint.textContent="Angiv sessionkode for at redigere round question-id.";}else if(!phase){roundQuestionGuardHint.textContent="Opdatér session-status for round question-id.";}else if(canEditRoundQuestion){roundQuestionGuardHint.textContent="Round question-id kan redigeres i fase: "+phaseLabel(phase)+".";}else{roundQuestionGuardHint.textContent="Round question-id er låst i fase: "+phaseLabel(phase)+".";}}if(categorySelect){categorySelect.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="lobby";}if(categoryGuardHint){if(hostActionInFlight){categoryGuardHint.textContent="Kategori er midlertidigt låst mens en handling kører.";}else if(sessionDetailInFlight){categoryGuardHint.textContent="Kategori er låst mens session-opdatering kører.";}else if(!hasCode){categoryGuardHint.textContent="Angiv sessionkode for at låse kategori til lobby-fasen.";}else if(phase==="lobby"){categoryGuardHint.textContent="Kategori kan vælges i lobby-fasen.";}else if(!phase){categoryGuardHint.textContent="Opdatér session-status for at validere kategori-lås.";}else{categoryGuardHint.textContent="Kategori er låst udenfor lobby-fasen.";}}if(!hint){return;}if(hostActionInFlight){hint.textContent="Handling kører… afvent svar før næste klik.";return;}if(sessionDetailInFlight){hint.textContent="Host-actions er låst mens session-opdatering kører.";return;}if(!hasCode){hint.textContent="Angiv sessionkode for at aktivere host-actions.";return;}if(!phase){hint.textContent="Opdatér session-status for fasebaserede host-actions.";return;}if(phase==="finished"){hint.textContent="Spillet er afsluttet: gameplay-actions er låst.";return;}if((phase==="lie"||phase==="guess")&&!hasRound){hint.textContent="Round question id mangler: mix/beregn score er låst.";return;}if(hostShellRouteHint){hint.textContent=hostShellRouteHint;return;}hint.textContent="Host-actions er klar for fase: "+phaseLabel(phase)+".";}
-async function api(path,method,payload){var o={method:method||"GET",headers:{"Accept":"application/json"}};if(payload!==null){o.headers["Content-Type"]="application/json";o.headers["X-CSRFToken"]=csrf();o.body=JSON.stringify(payload);}var r=await fetch(path,o);var d=await r.json().catch(function(){return {};});var isSessionDetailRead=(method||"GET")==="GET"&&/^\/lobby\/sessions\/[A-Z0-9]+$/.test(path);if(isSessionDetailRead){markSessionRefresh(r.status);}document.getElementById("out").textContent=JSON.stringify({status:r.status,data:d},null,2);if(d.session&&d.session.code){document.getElementById("code").value=d.session.code;}if(d.session&&d.session.status){currentSessionStatus=d.session.status;}if(d.round_question&&d.round_question.id){document.getElementById("roundQuestionId").value=d.round_question.id;}if(d.session){hydrateHostCriticalView(d);}updateErrorHint(r.status,d);updatePhaseStatus();syncStartRoundGuard(d);updateHostActionState();if(currentSessionStatus==="finished"&&autoRefreshEnabled){stopAutoRefresh("Auto-refresh stoppet: spillet er afsluttet.");}else{updateAutoRefreshUi();}if(hostShellFatalError){clearHostShellFatalError();}saveHostContext();return d;}
+function updateHostActionState(){updateCreateSessionState();var hasCode=!!code();var phase=currentSessionStatus||"";var nextRoundBtn=document.getElementById("nextRoundBtn");var finishGameBtn=document.getElementById("finishGameBtn");var roundQuestionGuardHint=document.getElementById("roundQuestionGuardHint");var categorySelect=document.getElementById("category");var categoryGuardHint=document.getElementById("categoryGuardHint");var hint=document.getElementById("hostActionHint");if(nextRoundBtn){nextRoundBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="scoreboard";}if(finishGameBtn){finishGameBtn.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="scoreboard";}if(roundQuestionGuardHint){if(hostActionInFlight){roundQuestionGuardHint.textContent="Round question-id er låst mens en handling kører.";}else if(sessionDetailInFlight){roundQuestionGuardHint.textContent="Round question-id er låst mens session-opdatering kører.";}else if(!hasCode){roundQuestionGuardHint.textContent="Angiv sessionkode for at se aktiv round question.";}else if(!phase){roundQuestionGuardHint.textContent="Opdatér session-status for round question-kontekst.";}else{roundQuestionGuardHint.textContent="Round question-id styres server-side i canonical flow og er read-only i fase: "+phaseLabel(phase)+".";}}if(categorySelect){categorySelect.disabled=hostActionInFlight||sessionDetailInFlight||!hasCode||phase!=="lobby";}if(categoryGuardHint){if(hostActionInFlight){categoryGuardHint.textContent="Kategori er midlertidigt låst mens en handling kører.";}else if(sessionDetailInFlight){categoryGuardHint.textContent="Kategori er låst mens session-opdatering kører.";}else if(!hasCode){categoryGuardHint.textContent="Angiv sessionkode for at låse kategori til lobby-fasen.";}else if(phase==="lobby"){categoryGuardHint.textContent="Kategori kan vælges i lobby-fasen.";}else if(!phase){categoryGuardHint.textContent="Opdatér session-status for at validere kategori-lås.";}else{categoryGuardHint.textContent="Kategori er låst udenfor lobby-fasen.";}}if(!hint){return;}if(hostActionInFlight){hint.textContent="Handling kører… afvent svar før næste klik.";return;}if(sessionDetailInFlight){hint.textContent="Host-actions er låst mens session-opdatering kører.";return;}if(!hasCode){hint.textContent="Angiv sessionkode for at aktivere host-actions.";return;}if(!phase){hint.textContent="Opdatér session-status for fasebaserede host-actions.";return;}if(phase==="finished"){hint.textContent="Spillet er afsluttet: gameplay-actions er låst.";return;}if(phase==="scoreboard"){hint.textContent="Host-actions er klar: vælg næste runde eller afslut spillet.";return;}if(hostShellRouteHint){hint.textContent=hostShellRouteHint;return;}hint.textContent="Mid-round faseskift er server-styrede i canonical flow. Host monitorerer kun fremdrift i fase: "+phaseLabel(phase)+".";}
+async function api(path,method,payload){var o={method:method||"GET",headers:{"Accept":"application/json"}};if(payload!==null){o.headers["Content-Type"]="application/json";o.headers["X-CSRFToken"]=csrf();o.body=JSON.stringify(payload);}var r=await fetch(path,o);var d=await r.json().catch(function(){return {};});var isSessionDetailRead=(method||"GET")==="GET"&&/^\/lobby\/sessions\/[A-Z0-9]+$/.test(path);if(isSessionDetailRead){markSessionRefresh(r.status);}document.getElementById("out").textContent=JSON.stringify({status:r.status,data:d},null,2);if(d.session&&d.session.code){document.getElementById("code").value=d.session.code;}if(d.session&&d.session.status){currentSessionStatus=d.session.status;}if(d.session){hydrateHostCriticalView(d);}updateErrorHint(r.status,d);updatePhaseStatus();syncStartRoundGuard(d);updateHostActionState();if(currentSessionStatus==="finished"&&autoRefreshEnabled){stopAutoRefresh("Auto-refresh stoppet: spillet er afsluttet.");}else{updateAutoRefreshUi();}if(hostShellFatalError){clearHostShellFatalError();}saveHostContext();return d;}
 
 function withHostActionLock(fn){if(hostActionInFlight){return Promise.resolve({error:"host_action_in_flight"});}hostActionInFlight=true;updateHostActionState();return Promise.resolve().then(fn).finally(function(){hostActionInFlight=false;updateHostActionState();});}
 function createSession(){return withHostActionLock(function(){return api("/lobby/sessions/create","POST",{});});} 
 function sessionDetail(){if(!code()){updateSessionDetailState();return Promise.resolve({error:"missing_session_code"});}if(sessionDetailInFlight){return Promise.resolve({error:"session_detail_in_flight"});}sessionDetailInFlight=true;updateSessionDetailState();return api("/lobby/sessions/"+code(),"GET",null).finally(function(){sessionDetailInFlight=false;updateSessionDetailState();});} 
 function startRound(){if(document.getElementById("startRoundBtn").disabled){return Promise.resolve({error:"not_enough_players_client_guard"});}return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/rounds/start","POST",{category_slug:document.getElementById("category").value});});}
-function showQuestion(){return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/questions/show","POST",{});});} 
-function mixAnswers(){return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/questions/"+rq()+"/answers/mix","POST",{});});} 
-function calcScores(){return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/questions/"+rq()+"/scores/calculate","POST",{});});} 
-function showScoreboard(){return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/scoreboard","GET",null);});} 
 function nextRound(){return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/rounds/next","POST",{});});} 
 function finishGame(){return withHostActionLock(function(){return api("/lobby/sessions/"+code()+"/finish","POST",{});});} 
-["code","roundQuestionId"].forEach(function(fieldId){var field=document.getElementById(fieldId);if(!field){return;}field.addEventListener("input",function(){syncStartRoundGuard(null);updateHostActionState();updateSessionDetailState();saveHostContext();});field.addEventListener("change",function(){syncStartRoundGuard(null);updateHostActionState();updateSessionDetailState();saveHostContext();});});
+["code"].forEach(function(fieldId){var field=document.getElementById(fieldId);if(!field){return;}field.addEventListener("input",function(){syncStartRoundGuard(null);updateHostActionState();updateSessionDetailState();saveHostContext();});field.addEventListener("change",function(){syncStartRoundGuard(null);updateHostActionState();updateSessionDetailState();saveHostContext();});});
 
 window.addEventListener("error",function(event){setHostShellFatalError((event&&event.message)||"Ukendt runtime-fejl");});
 window.addEventListener("unhandledrejection",function(event){var reason=event&&event.reason;var detail=(reason&&reason.message)||String(reason||"Unhandled promise rejection");setHostShellFatalError(detail);});

lobby/templates/lobby/player_screen.html

@@ -69,8 +69,12 @@
   <p id="playerCriticalRound">Round question: afventer</p>
   <p id="playerCriticalJoin">Join-status: afventer</p>
 </section>
-<pre id="out">Klar.</pre>
+<pre id="out">Ready.</pre>
+{{ lobby_i18n|json_script:"wppPlayerI18n" }}
 <script>
+var WPP_PLAYER_LOCALE="{{ shell_locale|default:'en'|escapejs }}";
+var WPP_PLAYER_I18N=JSON.parse(document.getElementById("wppPlayerI18n").textContent||"{}");
+function playerCopy(path,fallback){var node=WPP_PLAYER_I18N;var parts=(path||"").split(".");for(var i=0;i<parts.length;i++){if(!node||typeof node!=="object"){return fallback||path;}node=node[parts[i]];}if(node&&typeof node==="object"){if(node[WPP_PLAYER_LOCALE]){return node[WPP_PLAYER_LOCALE];}if(node.en){return node.en;}}return typeof node==="string"?node:(fallback||path);} 
 var availableAnswers=[];
 var guessSubmitted=false;
 var lieSubmitted=false;
@@ -89,6 +93,8 @@ var connectionRetryInFlight=false;
 var playerShellFatalError=false;
 var playerShellRecoverInFlight=false;
 var playerCriticalHydrated=false;
+function silencePlayerMediaElements(){if(typeof document==="undefined"||typeof document.querySelectorAll!=="function"){return;}var elements=document.querySelectorAll("audio,video");if(!elements||typeof elements.forEach!=="function"){return;}elements.forEach(function(element){if(!element){return;}element.muted=true;if(typeof element.pause==="function"){element.pause();}});}
+function installSecondaryDeviceAudioGuard(){if(typeof window==="undefined"){return;}silencePlayerMediaElements();var mediaProto=window.HTMLMediaElement&&window.HTMLMediaElement.prototype;if(!mediaProto||typeof mediaProto.play!=="function"){return;}if(mediaProto.__wppSecondaryDeviceAudioGuardInstalled){return;}mediaProto.__wppSecondaryDeviceAudioGuardInstalled=true;mediaProto.__wppSecondaryDeviceAudioGuardOriginalPlay=mediaProto.play;mediaProto.play=function(){return Promise.resolve();};}
 function setPlayerCriticalLoading(isLoading){var skeleton=document.getElementById("playerCriticalSkeleton");var view=document.getElementById("playerCriticalView");if(!skeleton||!view){return;}skeleton.style.display=isLoading?"block":"none";view.style.display=isLoading?"none":"block";}
 function hydratePlayerCriticalView(data){var phaseEl=document.getElementById("playerCriticalPhase");var roundEl=document.getElementById("playerCriticalRound");var joinEl=document.getElementById("playerCriticalJoin");if(phaseEl){phaseEl.textContent="Fase: "+phaseLabel(currentSessionStatus||((data&&data.session&&data.session.status)||""));}
 if(roundEl){roundEl.textContent="Round question: "+(rq()||"afventer");}
@@ -103,7 +109,7 @@ function clearPlayerShellFatalError(){playerShellFatalError=false;playerShellRec
 function recoverPlayerShell(mode){if(playerShellRecoverInFlight){return Promise.resolve({error:"recover_in_flight"});}playerShellRecoverInFlight=true;updatePlayerShellErrorBoundary();if(mode==="reload"){window.location.reload();return Promise.resolve({ok:true});}if(!code()){playerShellRecoverInFlight=false;updatePlayerShellErrorBoundary();return Promise.resolve({error:"missing_session_code"});}return sessionDetail().then(function(result){clearPlayerShellFatalError();return result;}).catch(function(err){playerShellRecoverInFlight=false;updatePlayerShellErrorBoundary();throw err;});}
 function pid(){return document.getElementById("playerId").value.trim();}
 function rq(){return document.getElementById("roundQuestionId").value.trim();}
-function phaseLabel(status){if(status==="lobby"){return"Lobby";}if(status==="lie"){return"Løgn";}if(status==="guess"){return"Gæt";}if(status==="reveal"){return"Reveal";}if(status==="finished"){return"Afsluttet";}return"Ukendt";}
+function phaseLabel(status){if(status==="lobby"){return"Lobby";}if(status==="lie"){return"Lie";}if(status==="guess"){return"Guess";}if(status==="reveal"){return"Reveal";}if(status==="scoreboard"){return"Scoreboard";}if(status==="finished"){return"Finished";}return"Unknown";}
 function updatePhaseStatus(){var el=document.getElementById("phaseStatus");if(!el){return;}if(!currentSessionStatus){el.textContent="Fase: ukendt (opdatér session-status).";return;}el.textContent="Fase: "+phaseLabel(currentSessionStatus)+" ("+currentSessionStatus+")";}
 function savePlayerContext(){try{localStorage.setItem(PLAYER_CONTEXT_KEY,JSON.stringify({code:code(),nickname:document.getElementById("nickname").value.trim(),player_id:pid(),session_token:document.getElementById("sessionToken").value.trim(),round_question_id:rq(),auto_refresh:playerAutoRefreshEnabled}));}catch(_e){}}
 function loadPlayerContext(){try{var raw=localStorage.getItem(PLAYER_CONTEXT_KEY);if(!raw){return null;}return JSON.parse(raw);}catch(_e){return null;}}
@@ -116,8 +122,8 @@ function resetRoundContextForManualChange(){document.getElementById("roundQuesti
 function updateContextLockState(){var locked=isPlayerContextLocked()||joinInFlight;var codeField=document.getElementById("code");var nicknameField=document.getElementById("nickname");var playerIdField=document.getElementById("playerId");var tokenField=document.getElementById("sessionToken");if(codeField){codeField.readOnly=locked;}if(nicknameField){nicknameField.readOnly=locked;}if(playerIdField){playerIdField.readOnly=locked;}if(tokenField){tokenField.readOnly=true;}var hint=document.getElementById("contextLockHint");if(!hint){return;}if(joinInFlight){hint.textContent="Låser kontekst…";return;}if(locked){hint.textContent="Spillerkontekst er låst efter join.";return;}hint.textContent="Kontekst er ikke låst endnu.";}
 function canAttemptJoin(){return !!(code()&&document.getElementById("nickname").value.trim());}
 function normalizeApiError(data){if(!data||typeof data!=="object"){return"";}return (data.error_code||data.error||"").toString();}
-function mapUiErrorMessage(errorKey){if(!errorKey){return"";}var key=errorKey.toLowerCase();if(key.indexOf("phase")!==-1){return"Ugyldig fase for handlingen. Opdatér session-status og prøv igen.";}if(key.indexOf("token")!==-1||key.indexOf("auth")!==-1){return"Session-token er ugyldig eller udløbet. Rejoin sessionen og prøv igen.";}if(key.indexOf("round")!==-1||key.indexOf("question")!==-1||key.indexOf("state")!==-1){return"Runde-kontekst matcher ikke længere. Opdatér session-status før næste handling.";}if(key.indexOf("session")!==-1){return"Sessionkoden er ugyldig eller sessionen findes ikke længere.";}return"Handling fejlede. Opdatér session-status og prøv igen.";}
-function formatTimeLabel(dateObj){return dateObj.toLocaleTimeString("da-DK",{hour12:false});}
+function mapUiErrorMessage(errorKey){if(!errorKey){return"";}var key=errorKey.toLowerCase();if(WPP_PLAYER_I18N&&WPP_PLAYER_I18N.backend&&WPP_PLAYER_I18N.backend.errors&&WPP_PLAYER_I18N.backend.errors[key]){return playerCopy("backend.errors."+key,"Action failed. Refresh state and retry.");}if(key.indexOf("session")!==-1){return playerCopy("backend.errors.session_not_found_or_closed","Session code is invalid, or session no longer exists.");}return playerCopy("backend.errors.generic_action_failed_retry","Action failed. Refresh state and retry.");}
+function formatTimeLabel(dateObj){return dateObj.toLocaleTimeString(WPP_PLAYER_LOCALE,{hour12:false});}
 function markPlayerSessionRefresh(status){if(status>=200&&status<300){playerLastRefreshAtLabel=formatTimeLabel(new Date());playerLastRefreshFailed=false;}else{playerLastRefreshFailed=true;}updatePlayerLastRefreshStatus();}
 function updatePlayerLastRefreshStatus(){var el=document.getElementById("playerLastRefreshStatus");if(!el){return;}if(!playerLastRefreshAtLabel){el.textContent=playerLastRefreshFailed?"Session-data kan være forældet (ingen succesfuld opdatering endnu).":"Session-data ikke opdateret endnu.";return;}if(playerLastRefreshFailed){el.textContent="Session-data kan være forældet (seneste succes: "+playerLastRefreshAtLabel+").";return;}el.textContent="Sidst opdateret: "+playerLastRefreshAtLabel+".";}
 function updatePlayerAutoRefreshUi(){var btn=document.getElementById("playerAutoRefreshToggleBtn");var hint=document.getElementById("playerAutoRefreshHint");if(btn){btn.textContent="Auto-refresh: "+(playerAutoRefreshEnabled?"ON":"OFF");btn.disabled=sessionDetailInFlight||joinInFlight||!code();}if(!hint){return;}if(sessionDetailInFlight){hint.textContent="Auto-refresh-lås: afvent aktiv session-opdatering.";return;}if(joinInFlight){hint.textContent="Auto-refresh-lås: afvent aktiv join.";return;}if(!code()){hint.textContent="Auto-refresh kræver sessionkode.";return;}if(!playerAutoRefreshEnabled){hint.textContent="Auto-refresh er slået fra.";return;}if(currentSessionStatus==="finished"){hint.textContent="Auto-refresh stoppet: spillet er afsluttet.";return;}hint.textContent="Auto-refresh aktiv (10s) for spillerstatus.";}
@@ -153,6 +159,7 @@ function submitGuess(){if(guessSubmitted){return Promise.resolve({error:"guess_a
 ["code","nickname","playerId","sessionToken","roundQuestionId"].forEach(function(fieldId){var field=document.getElementById(fieldId);if(!field){return;}field.addEventListener("input",function(){if(fieldId!=="roundQuestionId"){resetRoundContextForManualChange();}updateLieSubmitState();updateGuessSubmitState();updateJoinState();updateSessionDetailState();savePlayerContext();});field.addEventListener("change",function(){if(fieldId!=="roundQuestionId"){resetRoundContextForManualChange();}updateLieSubmitState();updateGuessSubmitState();updateJoinState();updateSessionDetailState();savePlayerContext();});});
 window.addEventListener("error",function(event){setPlayerShellFatalError((event&&event.message)||"Ukendt runtime-fejl");});
 window.addEventListener("unhandledrejection",function(event){var reason=event&&event.reason;var detail=(reason&&reason.message)||String(reason||"Unhandled promise rejection");setPlayerShellFatalError(detail);});
+installSecondaryDeviceAudioGuard();
 setPlayerCriticalLoading(true);
 updatePhaseStatus();
 updateGuessSubmitState();

lobby/templates/lobby/spa_shell.html

@@ -1,13 +1,13 @@
 <!doctype html>
-<html lang="da">
+<html lang="{{ shell_locale|default:'en' }}">
 <head>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>WPP SPA Shell</title>
-  <link rel="stylesheet" href="{{ spa_asset_base }}/styles.css">
+  <link rel="stylesheet" href="{{ spa_asset_base }}/styles.css?v={{ spa_asset_version|urlencode }}">
 </head>
-<body data-wpp-shell-route="{{ shell_route }}" data-wpp-shell-kind="{{ shell_kind }}">
-  <app-root data-wpp-shell-route="{{ shell_route }}" data-wpp-shell-kind="{{ shell_kind }}">Indlæser Angular app-shell…</app-root>
-  <script type="module" src="{{ spa_asset_base }}/main.js"></script>
+<body data-wpp-shell-route="{{ shell_route }}" data-wpp-shell-kind="{{ shell_kind }}" data-wpp-locale="{{ shell_locale|default:'en' }}">
+  <app-root data-wpp-shell-route="{{ shell_route }}" data-wpp-shell-kind="{{ shell_kind }}" data-wpp-locale="{{ shell_locale|default:'en' }}">Indlæser Angular app-shell…</app-root>
+  <script type="module" src="{{ spa_asset_base }}/main.js?v={{ spa_asset_version|urlencode }}"></script>
 </body>
 </html>

lobby/ui_views.py

@@ -5,7 +5,7 @@ from django.shortcuts import render
 from fupogfakta.models import Category
 
 from .feature_flags import use_spa_ui
-from .i18n import lobby_i18n_catalog
+from .i18n import lobby_i18n_catalog, resolve_locale
 
 
 def _render_spa_shell(request, shell_route: str, shell_kind: str):
@@ -16,7 +16,9 @@ def _render_spa_shell(request, shell_route: str, shell_kind: str):
             "shell_route": shell_route,
             "shell_kind": shell_kind,
             "spa_asset_base": settings.WPP_SPA_ASSET_BASE,
+            "spa_asset_version": getattr(settings, "WPP_SPA_ASSET_VERSION", "dev"),
             "lobby_i18n": lobby_i18n_catalog(),
+            "shell_locale": resolve_locale(request),
         },
     )
 
@@ -38,6 +40,7 @@ def host_screen(request, spa_path=None):
         {
             "categories": categories,
             "lobby_i18n": lobby_i18n_catalog(),
+            "shell_locale": resolve_locale(request),
         },
     )
 
@@ -46,4 +49,8 @@ def player_screen(request):
     if use_spa_ui():
         return _render_spa_shell(request, "/player", "player")
 
-    return render(request, "lobby/player_screen.html", {"lobby_i18n": lobby_i18n_catalog()})
+    return render(
+        request,
+        "lobby/player_screen.html",
+        {"lobby_i18n": lobby_i18n_catalog(), "shell_locale": resolve_locale(request)},
+    )

lobby/views.py

@@ -1,26 +1,38 @@
-import json
-import random
 from datetime import timedelta
 
+import json
+import random
 from django.contrib.auth.decorators import login_required
 from django.db import IntegrityError, transaction
 from django.http import HttpRequest, JsonResponse
 from django.utils import timezone
 from django.views.decorators.http import require_GET, require_POST
 
-from fupogfakta.models import (
-    Category,
-    GameSession,
-    Guess,
-    LieAnswer,
-    Player,
-    Question,
-    RoundConfig,
-    RoundQuestion,
-    ScoreEvent,
+from fupogfakta.models import GameSession, Guess, LieAnswer, Player, RoundConfig, RoundQuestion, ScoreEvent
+from fupogfakta.payloads import (
+    build_leaderboard as _build_leaderboard,
+    build_reveal_payload as _build_reveal_payload,
+    build_scoreboard_phase_event as _build_scoreboard_phase_event,
+    build_session_detail_gameplay_payload as _build_session_detail_gameplay_payload,
 )
+from fupogfakta.services import (
+    finish_game as _finish_game,
+    get_current_round_question as _get_current_round_question,
+    prepare_mixed_answers as _prepare_mixed_answers,
+    promote_reveal_to_scoreboard as _promote_reveal_to_scoreboard,
+    resolve_scores as _resolve_scores,
+    select_round_question as _select_round_question,
+    show_question as _show_question,
+    start_next_round as _start_next_round,
+    start_round as _start_round,
+)
+from realtime.broadcast import sync_broadcast_phase_event
+from .i18n import api_error
 
-from .i18n import api_error, lobby_i18n_errors
+_GAMEPLAY_SERVICE_OWNERSHIP_EXPORTS = (
+    _select_round_question,
+    _build_scoreboard_phase_event,
+)
 
 SESSION_CODE_ALPHABET = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789"
 SESSION_CODE_LENGTH = 6
@@ -30,8 +42,10 @@ JOINABLE_STATUSES = {
     GameSession.Status.LIE,
     GameSession.Status.GUESS,
     GameSession.Status.REVEAL,
+    GameSession.Status.SCOREBOARD,
 }
-ERROR_CODES = lobby_i18n_errors()
+
+
 
 
 def _json_body(request: HttpRequest) -> dict:
@@ -61,43 +75,17 @@ def _create_unique_session_code() -> str:
     raise RuntimeError("Could not generate unique session code")
 
 
-def _build_phase_view_model(session: GameSession, *, players_count: int, has_round_question: bool) -> dict:
-    status = session.status
-    in_lobby = status == GameSession.Status.LOBBY
-    in_lie = status == GameSession.Status.LIE
-    in_guess = status == GameSession.Status.GUESS
-    in_reveal = status == GameSession.Status.REVEAL
-    in_finished = status == GameSession.Status.FINISHED
 
-    min_players_reached = players_count >= 3
-    max_players_allowed = players_count <= 5
+def _maybe_promote_reveal_to_scoreboard(session: GameSession) -> GameSession:
+    transition = _promote_reveal_to_scoreboard(session)
+    if transition.should_broadcast:
+        sync_broadcast_phase_event(
+            transition.session.code,
+            transition.phase_event_name,
+            transition.phase_event_payload,
+        )
+    return transition.session
 
-    return {
-        "status": status,
-        "round_number": session.current_round,
-        "players_count": players_count,
-        "constraints": {
-            "min_players_to_start": 3,
-            "max_players_mvp": 5,
-            "min_players_reached": min_players_reached,
-            "max_players_allowed": max_players_allowed,
-        },
-        "host": {
-            "can_start_round": in_lobby and min_players_reached and max_players_allowed,
-            "can_show_question": in_lie and not has_round_question,
-            "can_mix_answers": in_lie or in_guess,
-            "can_calculate_scores": in_guess,
-            "can_reveal_scoreboard": in_reveal,
-            "can_start_next_round": in_reveal,
-            "can_finish_game": in_reveal,
-        },
-        "player": {
-            "can_join": status in JOINABLE_STATUSES,
-            "can_submit_lie": in_lie and has_round_question,
-            "can_submit_guess": in_guess and has_round_question,
-            "can_view_final_result": in_finished,
-        },
-    }
 
 
 @require_POST
@@ -128,15 +116,15 @@ def join_session(request: HttpRequest) -> JsonResponse:
 
     if not code:
         return api_error(
-            code=ERROR_CODES.get("session_code_required", "session_code_required"),
-            message="Session code is required",
+            request,
+            code="session_code_required",
             status=400,
         )
 
     if len(nickname) < 2 or len(nickname) > 40:
         return api_error(
-            code=ERROR_CODES.get("nickname_invalid", "nickname_invalid"),
-            message="Nickname must be between 2 and 40 characters",
+            request,
+            code="nickname_invalid",
             status=400,
         )
 
@@ -144,22 +132,22 @@ def join_session(request: HttpRequest) -> JsonResponse:
         session = GameSession.objects.get(code=code)
     except GameSession.DoesNotExist:
         return api_error(
-            code=ERROR_CODES.get("session_not_found", "session_not_found"),
-            message="Session not found",
+            request,
+            code="session_not_found",
             status=404,
         )
 
     if session.status not in JOINABLE_STATUSES:
         return api_error(
-            code=ERROR_CODES.get("session_not_joinable", "session_not_joinable"),
-            message="Session is not joinable",
+            request,
+            code="session_not_joinable",
             status=400,
         )
 
     if Player.objects.filter(session=session, nickname__iexact=nickname).exists():
         return api_error(
-            code=ERROR_CODES.get("nickname_taken", "nickname_taken"),
-            message="Nickname already taken",
+            request,
+            code="nickname_taken",
             status=409,
         )
 
@@ -190,8 +178,8 @@ def session_detail(request: HttpRequest, code: str) -> JsonResponse:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
         return api_error(
-            code=ERROR_CODES.get("session_not_found", "session_not_found"),
-            message="Session not found",
+            request,
+            code="session_not_found",
             status=404,
         )
 
@@ -204,27 +192,12 @@ def session_detail(request: HttpRequest, code: str) -> JsonResponse:
         )
     )
 
-    current_round_question = (
-        RoundQuestion.objects.filter(session=session, round_number=session.current_round)
-        .select_related("question")
-        .order_by("-id")
-        .first()
-    )
-
-    round_question_payload = None
-    if current_round_question:
-        round_question_payload = {
-            "id": current_round_question.id,
-            "round_number": current_round_question.round_number,
-            "prompt": current_round_question.question.prompt,
-            "shown_at": current_round_question.shown_at.isoformat(),
-            "answers": [{"text": text} for text in (current_round_question.mixed_answers or [])],
-        }
-
-    phase_view_model = _build_phase_view_model(
+    session = _maybe_promote_reveal_to_scoreboard(session)
+    current_round_question = _get_current_round_question(session)
+    gameplay_payload = _build_session_detail_gameplay_payload(
         session,
+        current_round_question=current_round_question,
         players_count=len(players),
-        has_round_question=bool(current_round_question),
     )
 
     return JsonResponse(
@@ -237,8 +210,7 @@ def session_detail(request: HttpRequest, code: str) -> JsonResponse:
                 "players_count": len(players),
             },
             "players": players,
-            "round_question": round_question_payload,
-            "phase_view_model": phase_view_model,
+            **gameplay_payload,
         }
     )
 
@@ -251,8 +223,8 @@ def start_round(request: HttpRequest, code: str) -> JsonResponse:
 
     if not category_slug:
         return api_error(
-            code=ERROR_CODES.get("category_slug_required", "category_slug_required"),
-            message="category_slug is required",
+            request,
+            code="category_slug_required",
             status=400,
         )
 
@@ -262,75 +234,36 @@ def start_round(request: HttpRequest, code: str) -> JsonResponse:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
         return api_error(
-            code=ERROR_CODES.get("session_not_found", "session_not_found"),
-            message="Session not found",
+            request,
+            code="session_not_found",
             status=404,
         )
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can start round"}, status=403)
-
-    if session.status != GameSession.Status.LOBBY:
         return api_error(
-            code=ERROR_CODES.get("round_start_invalid_phase", "round_start_invalid_phase"),
-            message="Round can only be started from lobby",
-            status=400,
+            request,
+            code="host_only_start_round",
+            status=403,
         )
 
     try:
-        category = Category.objects.get(slug=category_slug, is_active=True)
-    except Category.DoesNotExist:
-        return api_error(
-            code=ERROR_CODES.get("category_not_found", "category_not_found"),
-            message="Category not found",
-            status=404,
-        )
+        transition = _start_round(session, category_slug)
+    except ValueError as exc:
+        error_code = str(exc)
+        error_status = {
+            "category_not_found": 404,
+            "round_already_configured": 409,
+        }.get(error_code, 400)
+        return api_error(request, code=error_code, status=error_status)
 
-    if not Question.objects.filter(category=category, is_active=True).exists():
-        return JsonResponse({"error": "Category has no active questions"}, status=400)
-
-    with transaction.atomic():
-        session = GameSession.objects.select_for_update().get(pk=session.pk)
-        if session.status != GameSession.Status.LOBBY:
-            return api_error(
-                code=ERROR_CODES.get("round_start_invalid_phase", "round_start_invalid_phase"),
-                message="Round can only be started from lobby",
-                status=400,
-            )
-
-        round_config, created = RoundConfig.objects.get_or_create(
-            session=session,
-            number=session.current_round,
-            defaults={"category": category},
-        )
-        if not created:
-            return api_error(
-                code=ERROR_CODES.get("round_already_configured", "round_already_configured"),
-                message="Round already configured",
-                status=409,
-            )
-
-        session.status = GameSession.Status.LIE
-        session.save(update_fields=["status"])
-
-    return JsonResponse(
-        {
-            "session": {
-                "code": session.code,
-                "status": session.status,
-                "current_round": session.current_round,
-            },
-            "round": {
-                "number": round_config.number,
-                "category": {
-                    "slug": round_config.category.slug,
-                    "name": round_config.category.name,
-                },
-            },
-        },
-        status=201,
+    sync_broadcast_phase_event(
+        transition.session.code,
+        transition.phase_event_name,
+        transition.phase_event_payload,
     )
 
+    return JsonResponse(transition.response_payload, status=201)
+
 
 @require_POST
 @login_required
@@ -340,56 +273,31 @@ def show_question(request: HttpRequest, code: str) -> JsonResponse:
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(
+            request,
+            code="session_not_found",
+            status=404,
+        )
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can show question"}, status=403)
-
-    if session.status != GameSession.Status.LIE:
-        return JsonResponse({"error": "Question can only be shown in lie phase"}, status=400)
+        return api_error(
+            request,
+            code="host_only_show_question",
+            status=403,
+        )
 
     try:
-        round_config = RoundConfig.objects.get(session=session, number=session.current_round)
-    except RoundConfig.DoesNotExist:
-        return JsonResponse({"error": "Round config missing"}, status=400)
+        transition = _show_question(session)
+    except ValueError as exc:
+        return api_error(request, code=str(exc), status=400)
 
-    if RoundQuestion.objects.filter(session=session, round_number=session.current_round).exists():
-        return JsonResponse({"error": "Question already shown for this round"}, status=409)
-
-    used_question_ids = RoundQuestion.objects.filter(session=session).values_list("question_id", flat=True)
-    available_questions = Question.objects.filter(
-        category=round_config.category,
-        is_active=True,
-    ).exclude(pk__in=used_question_ids)
-
-    if not available_questions.exists():
-        return JsonResponse({"error": "No available questions in category"}, status=400)
-
-    question = random.choice(list(available_questions))
-    round_question = RoundQuestion.objects.create(
-        session=session,
-        round_number=session.current_round,
-        question=question,
-        correct_answer=question.correct_answer,
+    sync_broadcast_phase_event(
+        transition.session.code,
+        transition.phase_event_name,
+        transition.phase_event_payload,
     )
 
-    lie_deadline_at = round_question.shown_at + timedelta(seconds=round_config.lie_seconds)
-
-    return JsonResponse(
-        {
-            "round_question": {
-                "id": round_question.id,
-                "prompt": question.prompt,
-                "round_number": round_question.round_number,
-                "shown_at": round_question.shown_at.isoformat(),
-                "lie_deadline_at": lie_deadline_at.isoformat(),
-            },
-            "config": {
-                "lie_seconds": round_config.lie_seconds,
-            },
-        },
-        status=201,
-    )
+    return JsonResponse(transition.response_payload, status=201)
 
 
 @require_POST
@@ -402,29 +310,29 @@ def submit_lie(request: HttpRequest, code: str, round_question_id: int) -> JsonR
     lie_text = str(payload.get("text", "")).strip()
 
     if not player_id:
-        return JsonResponse({"error": "player_id is required"}, status=400)
+        return api_error(request, code="player_id_required", status=400)
 
     if not session_token:
-        return JsonResponse({"error": "session_token is required"}, status=400)
+        return api_error(request, code="session_token_required", status=400)
 
     if not lie_text or len(lie_text) > 255:
-        return JsonResponse({"error": "text must be between 1 and 255 characters"}, status=400)
+        return api_error(request, code="lie_text_invalid", status=400)
 
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(request, code="session_not_found", status=404)
 
     if session.status != GameSession.Status.LIE:
-        return JsonResponse({"error": "Lie submission is only allowed in lie phase"}, status=400)
+        return api_error(request, code="lie_submission_invalid_phase", status=400)
 
     try:
         player = Player.objects.get(pk=player_id, session=session)
     except Player.DoesNotExist:
-        return JsonResponse({"error": "Player not found in session"}, status=404)
+        return api_error(request, code="player_not_found_in_session", status=404)
 
     if player.session_token != session_token:
-        return JsonResponse({"error": "Invalid player session token"}, status=403)
+        return api_error(request, code="invalid_player_session_token", status=403)
 
     try:
         round_question = RoundQuestion.objects.get(
@@ -433,21 +341,46 @@ def submit_lie(request: HttpRequest, code: str, round_question_id: int) -> JsonR
             round_number=session.current_round,
         )
     except RoundQuestion.DoesNotExist:
-        return JsonResponse({"error": "Round question not found"}, status=404)
+        return api_error(request, code="round_question_not_found", status=404)
 
     try:
         round_config = RoundConfig.objects.get(session=session, number=round_question.round_number)
     except RoundConfig.DoesNotExist:
-        return JsonResponse({"error": "Round config missing"}, status=400)
+        return api_error(request, code="round_config_missing", status=400)
 
     lie_deadline_at = round_question.shown_at + timedelta(seconds=round_config.lie_seconds)
     if timezone.now() > lie_deadline_at:
-        return JsonResponse({"error": "Lie submission window has closed"}, status=400)
+        return api_error(request, code="lie_submission_closed", status=400)
 
     try:
         lie = LieAnswer.objects.create(round_question=round_question, player=player, text=lie_text)
     except IntegrityError:
-        return JsonResponse({"error": "Lie already submitted for this player"}, status=409)
+        return api_error(request, code="lie_already_submitted", status=409)
+
+    players_count = Player.objects.filter(session=session).count()
+    lie_count = LieAnswer.objects.filter(round_question=round_question).count()
+    session_status = session.status
+    mixed_answers_payload = None
+
+    if players_count > 0 and lie_count >= players_count:
+        try:
+            mixed_answers = _prepare_mixed_answers(round_question)
+        except ValueError as exc:
+            return api_error(request, code=str(exc), status=400)
+
+        session.status = GameSession.Status.GUESS
+        session.save(update_fields=["status"])
+        session_status = session.status
+        mixed_answers_payload = [{"text": text} for text in mixed_answers]
+        sync_broadcast_phase_event(
+            session.code,
+            "phase.guess_started",
+            {
+                "round_question_id": round_question.id,
+                "answers": mixed_answers_payload,
+                "guess_seconds": round_config.guess_seconds,
+            },
+        )
 
     return JsonResponse(
         {
@@ -461,6 +394,18 @@ def submit_lie(request: HttpRequest, code: str, round_question_id: int) -> JsonR
             "window": {
                 "lie_deadline_at": lie_deadline_at.isoformat(),
             },
+            "session": {
+                "code": session.code,
+                "status": session_status,
+                "current_round": session.current_round,
+            },
+            "phase_transition": {
+                "current_phase": session_status,
+                "lies_submitted": lie_count,
+                "players_expected": players_count,
+                "auto_advanced": session_status == GameSession.Status.GUESS,
+            },
+            "answers": mixed_answers_payload,
         },
         status=201,
     )
@@ -473,13 +418,25 @@ def mix_answers(request: HttpRequest, code: str, round_question_id: int) -> Json
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(
+            request,
+            code="session_not_found",
+            status=404,
+        )
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can mix answers"}, status=403)
+        return api_error(
+            request,
+            code="host_only_mix_answers",
+            status=403,
+        )
 
     if session.status not in {GameSession.Status.LIE, GameSession.Status.GUESS}:
-        return JsonResponse({"error": "Answers can only be mixed in lie or guess phase"}, status=400)
+        return api_error(
+            request,
+            code="mix_answers_invalid_phase",
+            status=400,
+        )
 
     try:
         round_question = RoundQuestion.objects.get(
@@ -488,37 +445,48 @@ def mix_answers(request: HttpRequest, code: str, round_question_id: int) -> Json
             round_number=session.current_round,
         )
     except RoundQuestion.DoesNotExist:
-        return JsonResponse({"error": "Round question not found"}, status=404)
+        return api_error(
+            request,
+            code="round_question_not_found",
+            status=404,
+        )
 
     with transaction.atomic():
         locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
         if locked_session.status not in {GameSession.Status.LIE, GameSession.Status.GUESS}:
-            return JsonResponse({"error": "Answers can only be mixed in lie or guess phase"}, status=400)
+            return api_error(
+                request,
+                code="mix_answers_invalid_phase",
+                status=400,
+            )
 
         locked_round_question = RoundQuestion.objects.select_for_update().get(pk=round_question.pk)
 
-        deduped_answers = list(locked_round_question.mixed_answers or [])
-        if not deduped_answers:
-            lie_texts = list(locked_round_question.lies.values_list("text", flat=True))
-            seen = set()
-            for text in [locked_round_question.correct_answer, *lie_texts]:
-                normalized = text.strip().casefold()
-                if not normalized or normalized in seen:
-                    continue
-                seen.add(normalized)
-                deduped_answers.append(text.strip())
-
-            if len(deduped_answers) < 2:
-                return JsonResponse({"error": "Not enough answers to mix"}, status=400)
-
-            random.shuffle(deduped_answers)
-            locked_round_question.mixed_answers = deduped_answers
-            locked_round_question.save(update_fields=["mixed_answers"])
+        try:
+            deduped_answers = _prepare_mixed_answers(locked_round_question)
+        except ValueError as exc:
+            return api_error(request, code=str(exc), status=400)
 
         if locked_session.status == GameSession.Status.LIE:
             locked_session.status = GameSession.Status.GUESS
             locked_session.save(update_fields=["status"])
 
+    try:
+        _guess_config = RoundConfig.objects.get(session=session, number=session.current_round)
+        _guess_seconds = _guess_config.guess_seconds
+    except RoundConfig.DoesNotExist:
+        _guess_seconds = None
+
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.guess_started",
+        {
+            "round_question_id": round_question.id,
+            "answers": [{"text": t} for t in deduped_answers],
+            "guess_seconds": _guess_seconds,
+        },
+    )
+
     return JsonResponse(
         {
             "session": {
@@ -545,29 +513,29 @@ def submit_guess(request: HttpRequest, code: str, round_question_id: int) -> Jso
     selected_text = str(payload.get("selected_text", "")).strip()
 
     if not player_id:
-        return JsonResponse({"error": "player_id is required"}, status=400)
+        return api_error(request, code="player_id_required", status=400)
 
     if not session_token:
-        return JsonResponse({"error": "session_token is required"}, status=400)
+        return api_error(request, code="session_token_required", status=400)
 
     if not selected_text or len(selected_text) > 255:
-        return JsonResponse({"error": "selected_text must be between 1 and 255 characters"}, status=400)
+        return api_error(request, code="selected_text_invalid", status=400)
 
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(request, code="session_not_found", status=404)
 
     if session.status != GameSession.Status.GUESS:
-        return JsonResponse({"error": "Guess submission is only allowed in guess phase"}, status=400)
+        return api_error(request, code="guess_submission_invalid_phase", status=400)
 
     try:
         player = Player.objects.get(pk=player_id, session=session)
     except Player.DoesNotExist:
-        return JsonResponse({"error": "Player not found in session"}, status=404)
+        return api_error(request, code="player_not_found_in_session", status=404)
 
     if player.session_token != session_token:
-        return JsonResponse({"error": "Invalid player session token"}, status=403)
+        return api_error(request, code="invalid_player_session_token", status=403)
 
     try:
         round_question = RoundQuestion.objects.get(
@@ -576,18 +544,18 @@ def submit_guess(request: HttpRequest, code: str, round_question_id: int) -> Jso
             round_number=session.current_round,
         )
     except RoundQuestion.DoesNotExist:
-        return JsonResponse({"error": "Round question not found"}, status=404)
+        return api_error(request, code="round_question_not_found", status=404)
 
     try:
         round_config = RoundConfig.objects.get(session=session, number=round_question.round_number)
     except RoundConfig.DoesNotExist:
-        return JsonResponse({"error": "Round config missing"}, status=400)
+        return api_error(request, code="round_config_missing", status=400)
 
     guess_deadline_at = round_question.shown_at + timedelta(
         seconds=round_config.lie_seconds + round_config.guess_seconds
     )
     if timezone.now() > guess_deadline_at:
-        return JsonResponse({"error": "Guess submission window has closed"}, status=400)
+        return api_error(request, code="guess_submission_closed", status=400)
 
     allowed_answers = {
         round_question.correct_answer.strip().casefold(),
@@ -600,7 +568,7 @@ def submit_guess(request: HttpRequest, code: str, round_question_id: int) -> Jso
 
     selected_normalized = selected_text.casefold()
     if selected_normalized not in allowed_answers:
-        return JsonResponse({"error": "Selected answer is not part of this round"}, status=400)
+        return api_error(request, code="selected_answer_invalid", status=400)
 
     correct_normalized = round_question.correct_answer.strip().casefold()
     fooled_player_id = None
@@ -618,7 +586,68 @@ def submit_guess(request: HttpRequest, code: str, round_question_id: int) -> Jso
             fooled_player_id=fooled_player_id,
         )
     except IntegrityError:
-        return JsonResponse({"error": "Guess already submitted for this player"}, status=409)
+        return api_error(request, code="guess_already_submitted", status=409)
+
+    players_count = Player.objects.filter(session=session).count()
+    guess_count = Guess.objects.filter(round_question=round_question).count()
+    session_status = session.status
+    reveal_payload = None
+    leaderboard = None
+
+    if players_count > 0 and guess_count >= players_count:
+        score_events = []
+        should_broadcast_scores = False
+
+        with transaction.atomic():
+            locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
+
+            if locked_session.status == GameSession.Status.GUESS:
+                already_calculated = ScoreEvent.objects.filter(
+                    session=locked_session,
+                    meta__round_question_id=round_question.id,
+                ).exists()
+                if not already_calculated:
+                    score_events, leaderboard = _resolve_scores(locked_session, round_question, round_config)
+                    should_broadcast_scores = True
+                else:
+                    score_events = list(
+                        ScoreEvent.objects.filter(
+                            session=locked_session,
+                            meta__round_question_id=round_question.id,
+                        ).select_related("player")
+                    )
+                    leaderboard = _build_leaderboard(locked_session)
+
+                locked_session.status = GameSession.Status.REVEAL
+                locked_session.save(update_fields=["status"])
+
+            elif locked_session.status == GameSession.Status.REVEAL:
+                score_events = list(
+                    ScoreEvent.objects.filter(
+                        session=locked_session,
+                        meta__round_question_id=round_question.id,
+                    ).select_related("player")
+                )
+                leaderboard = _build_leaderboard(locked_session)
+
+            session_status = locked_session.status
+
+        reveal_payload = _build_reveal_payload(round_question)
+
+        if should_broadcast_scores:
+            score_deltas = [
+                {"player_id": ev.player_id, "delta": ev.delta, "reason": ev.reason}
+                for ev in score_events
+            ]
+            sync_broadcast_phase_event(
+                session.code,
+                "phase.scores_calculated",
+                {
+                    "round_question_id": round_question.id,
+                    "score_deltas": score_deltas,
+                    "leaderboard": list(leaderboard),
+                },
+            )
 
     return JsonResponse(
         {
@@ -634,6 +663,19 @@ def submit_guess(request: HttpRequest, code: str, round_question_id: int) -> Jso
             "window": {
                 "guess_deadline_at": guess_deadline_at.isoformat(),
             },
+            "session": {
+                "code": session.code,
+                "status": session_status,
+                "current_round": session.current_round,
+            },
+            "phase_transition": {
+                "current_phase": session_status,
+                "guesses_submitted": guess_count,
+                "players_expected": players_count,
+                "auto_advanced": session_status == GameSession.Status.REVEAL,
+            },
+            "reveal": reveal_payload,
+            "leaderboard": leaderboard,
         },
         status=201,
     )
@@ -649,30 +691,23 @@ def reveal_scoreboard(request: HttpRequest, code: str) -> JsonResponse:
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(request, code="session_not_found", status=404)
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can view scoreboard"}, status=403)
+        return api_error(request, code="host_only_view_scoreboard", status=403)
 
-    if session.status != GameSession.Status.REVEAL:
-        return JsonResponse({"error": "Scoreboard is only available in reveal phase"}, status=400)
+    transition = _promote_reveal_to_scoreboard(session)
+    if transition.should_broadcast:
+        sync_broadcast_phase_event(
+            transition.session.code,
+            transition.phase_event_name,
+            transition.phase_event_payload,
+        )
+    session = transition.session
+    if session.status not in {GameSession.Status.SCOREBOARD, GameSession.Status.FINISHED}:
+        return api_error(request, code="scoreboard_invalid_phase", status=400)
 
-    leaderboard = list(
-        Player.objects.filter(session=session)
-        .order_by("-score", "nickname")
-        .values("id", "nickname", "score")
-    )
-
-    return JsonResponse(
-        {
-            "session": {
-                "code": session.code,
-                "status": session.status,
-                "current_round": session.current_round,
-            },
-            "leaderboard": leaderboard,
-        }
-    )
+    return JsonResponse(transition.response_payload)
 
 
 @require_POST
@@ -683,29 +718,24 @@ def start_next_round(request: HttpRequest, code: str) -> JsonResponse:
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(request, code="session_not_found", status=404)
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can start next round"}, status=403)
+        return api_error(request, code="host_only_start_next_round", status=403)
 
-    with transaction.atomic():
-        locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
-        if locked_session.status != GameSession.Status.REVEAL:
-            return JsonResponse({"error": "Next round can only start from reveal phase"}, status=400)
+    try:
+        transition = _start_next_round(session)
+    except ValueError as exc:
+        return api_error(request, code=str(exc), status=400)
 
-        locked_session.current_round += 1
-        locked_session.status = GameSession.Status.LOBBY
-        locked_session.save(update_fields=["current_round", "status"])
+    if transition.should_broadcast:
+        sync_broadcast_phase_event(
+            transition.session.code,
+            transition.phase_event_name,
+            transition.phase_event_payload,
+        )
 
-    return JsonResponse(
-        {
-            "session": {
-                "code": session.code,
-                "status": GameSession.Status.LOBBY,
-                "current_round": locked_session.current_round,
-            }
-        }
-    )
+    return JsonResponse(transition.response_payload)
 
 @require_POST
 @login_required
@@ -715,38 +745,24 @@ def finish_game(request: HttpRequest, code: str) -> JsonResponse:
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(request, code="session_not_found", status=404)
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can finish game"}, status=403)
+        return api_error(request, code="host_only_finish_game", status=403)
 
-    with transaction.atomic():
-        locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
-        if locked_session.status != GameSession.Status.REVEAL:
-            return JsonResponse({"error": "Game can only be finished from reveal phase"}, status=400)
+    try:
+        transition = _finish_game(session)
+    except ValueError as exc:
+        return api_error(request, code=str(exc), status=400)
 
-        locked_session.status = GameSession.Status.FINISHED
-        locked_session.save(update_fields=["status"])
+    if transition.should_broadcast:
+        sync_broadcast_phase_event(
+            transition.session.code,
+            transition.phase_event_name,
+            transition.phase_event_payload,
+        )
 
-    leaderboard = list(
-        Player.objects.filter(session=session)
-        .order_by("-score", "nickname")
-        .values("id", "nickname", "score")
-    )
-
-    winner = leaderboard[0] if leaderboard else None
-
-    return JsonResponse(
-        {
-            "session": {
-                "code": session.code,
-                "status": GameSession.Status.FINISHED,
-                "current_round": session.current_round,
-            },
-            "winner": winner,
-            "leaderboard": leaderboard,
-        }
-    )
+    return JsonResponse(transition.response_payload)
 
 
 @require_POST
@@ -757,20 +773,20 @@ def calculate_scores(request: HttpRequest, code: str, round_question_id: int) ->
     try:
         session = GameSession.objects.get(code=session_code)
     except GameSession.DoesNotExist:
-        return JsonResponse({"error": "Session not found"}, status=404)
+        return api_error(request, code="session_not_found", status=404)
 
     if session.host_id != request.user.id:
-        return JsonResponse({"error": "Only host can calculate scores"}, status=403)
+        return api_error(request, code="host_only_calculate_scores", status=403)
 
     already_calculated = ScoreEvent.objects.filter(
         session=session,
         meta__round_question_id=round_question_id,
     ).exists()
     if already_calculated:
-        return JsonResponse({"error": "Scores already calculated for this round question"}, status=409)
+        return api_error(request, code="scores_already_calculated", status=409)
 
     if session.status != GameSession.Status.GUESS:
-        return JsonResponse({"error": "Scores can only be calculated in guess phase"}, status=400)
+        return api_error(request, code="calculate_scores_invalid_phase", status=400)
 
     try:
         round_question = RoundQuestion.objects.get(
@@ -779,16 +795,16 @@ def calculate_scores(request: HttpRequest, code: str, round_question_id: int) ->
             round_number=session.current_round,
         )
     except RoundQuestion.DoesNotExist:
-        return JsonResponse({"error": "Round question not found"}, status=404)
+        return api_error(request, code="round_question_not_found", status=404)
 
     try:
         round_config = RoundConfig.objects.get(session=session, number=round_question.round_number)
     except RoundConfig.DoesNotExist:
-        return JsonResponse({"error": "Round config missing"}, status=400)
+        return api_error(request, code="round_config_missing", status=400)
 
     guesses = list(round_question.guesses.select_related("player"))
     if not guesses:
-        return JsonResponse({"error": "No guesses submitted for this round question"}, status=400)
+        return api_error(request, code="no_guesses_submitted", status=400)
 
     bluff_counts = {}
     for guess in guesses:
@@ -798,7 +814,7 @@ def calculate_scores(request: HttpRequest, code: str, round_question_id: int) ->
     with transaction.atomic():
         locked_session = GameSession.objects.select_for_update().get(pk=session.pk)
         if locked_session.status != GameSession.Status.GUESS:
-            return JsonResponse({"error": "Scores can only be calculated in guess phase"}, status=400)
+            return api_error(request, code="calculate_scores_invalid_phase", status=400)
 
         score_events = []
 
@@ -842,6 +858,21 @@ def calculate_scores(request: HttpRequest, code: str, round_question_id: int) ->
         .values("id", "nickname", "score")
     )
 
+    score_deltas = [
+        {"player_id": ev.player_id, "delta": ev.delta, "reason": ev.reason}
+        for ev in score_events
+    ]
+
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.scores_calculated",
+        {
+            "round_question_id": round_question.id,
+            "score_deltas": score_deltas,
+            "leaderboard": list(leaderboard),
+        },
+    )
+
     return JsonResponse(
         {
             "session": {
@@ -853,6 +884,7 @@ def calculate_scores(request: HttpRequest, code: str, round_question_id: int) ->
                 "id": round_question.id,
                 "round_number": round_question.round_number,
             },
+            "reveal": _build_reveal_payload(round_question),
             "events_created": len(score_events),
             "leaderboard": leaderboard,
         }

partyhub/asgi.py

@@ -1,11 +1,15 @@
 import os
-from channels.routing import ProtocolTypeRouter
+
+from channels.routing import ProtocolTypeRouter, URLRouter
 from django.core.asgi import get_asgi_application
 
 os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'partyhub.settings')
 
 django_asgi_app = get_asgi_application()
 
+from realtime.routing import websocket_urlpatterns  # noqa: E402 — must come after env setup
+
 application = ProtocolTypeRouter({
     'http': django_asgi_app,
+    'websocket': URLRouter(websocket_urlpatterns),
 })

partyhub/i18n_bootstrap.py

@@ -0,0 +1,30 @@
+import json
+from functools import lru_cache
+from pathlib import Path
+
+_LOCALE_LABELS = {
+    "en": "English",
+    "da": "Danish",
+}
+
+
+@lru_cache(maxsize=1)
+def shared_i18n_catalog() -> dict:
+    catalog_path = Path(__file__).resolve().parents[1] / "shared" / "i18n" / "lobby.json"
+    with catalog_path.open(encoding="utf-8") as handle:
+        return json.load(handle)
+
+
+@lru_cache(maxsize=1)
+def locale_config() -> tuple[str, tuple[str, ...]]:
+    locales = shared_i18n_catalog().get("locales", {})
+    default_locale = str(locales.get("default", "en")).strip().lower() or "en"
+    supported_locales = tuple(
+        locale.strip().lower() for locale in locales.get("supported", ["en", "da"]) if str(locale).strip()
+    ) or ("en", "da")
+    return default_locale, supported_locales
+
+
+def django_languages() -> list[tuple[str, str]]:
+    _default_locale, supported_locales = locale_config()
+    return [(locale, _LOCALE_LABELS.get(locale, locale.upper())) for locale in supported_locales]

partyhub/settings.py

@@ -1,6 +1,8 @@
 from pathlib import Path
 import os
 
+from partyhub.i18n_bootstrap import django_languages, locale_config
+
 BASE_DIR = Path(__file__).resolve().parent.parent
 
 
@@ -30,6 +32,7 @@ INSTALLED_APPS = [
 MIDDLEWARE = [
     'django.middleware.security.SecurityMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.locale.LocaleMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
@@ -89,7 +92,9 @@ AUTH_PASSWORD_VALIDATORS = [
     {'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator'},
 ]
 
-LANGUAGE_CODE = 'da'
+LANGUAGE_CODE, _SUPPORTED_LOCALES = locale_config()
+LANGUAGES = django_languages()
+LOCALE_PATHS = [BASE_DIR / 'locale']
 TIME_ZONE = 'Europe/Copenhagen'
 USE_I18N = True
 USE_TZ = True
@@ -105,11 +110,19 @@ if USE_SPA_UI_RAW is None:
     USE_SPA_UI_RAW = env('WPP_SPA_ENABLED', 'false')
 USE_SPA_UI = USE_SPA_UI_RAW.lower() == 'true'
 WPP_SPA_ASSET_BASE = env('WPP_SPA_ASSET_BASE', '/static/frontend/angular/browser').rstrip('/')
+# Cache-busting token for SPA shell static asset URLs (querystring versioning).
+# Set to release id / commit SHA in deploy env for deterministic invalidation.
+WPP_SPA_ASSET_VERSION = env('WPP_SPA_ASSET_VERSION', 'dev')
 
 CHANNEL_REDIS_HOST = env('CHANNEL_REDIS_HOST', '127.0.0.1')
 CHANNEL_REDIS_PORT = int(env('CHANNEL_REDIS_PORT', '6379'))
+
+import sys  # noqa: E402
+_testing = 'test' in sys.argv
 CHANNEL_LAYERS = {
     'default': {
+        'BACKEND': 'channels.layers.InMemoryChannelLayer',
+    } if _testing else {
         'BACKEND': 'channels_redis.core.RedisChannelLayer',
         'CONFIG': {'hosts': [(CHANNEL_REDIS_HOST, CHANNEL_REDIS_PORT)]},
     }

partyhub/tests_i18n_bootstrap.py

@@ -0,0 +1,28 @@
+from django.conf import settings
+from django.test import TestCase
+
+from partyhub.i18n_bootstrap import django_languages, locale_config, shared_i18n_catalog
+
+
+class I18nBootstrapTests(TestCase):
+    def test_shared_catalog_bootstraps_default_and_supported_locales(self):
+        default_locale, supported_locales = locale_config()
+
+        self.assertEqual(default_locale, "en")
+        self.assertEqual(supported_locales, ("en", "da"))
+
+    def test_django_language_settings_bootstrap_from_shared_i18n_catalog(self):
+        default_locale, supported_locales = locale_config()
+
+        self.assertEqual(settings.LANGUAGE_CODE, default_locale)
+        self.assertEqual(tuple(code for code, _ in settings.LANGUAGES), supported_locales)
+        self.assertEqual(settings.LANGUAGES, django_languages())
+
+    def test_locale_contract_in_catalog_matches_django_language_codes(self):
+        catalog_locales = shared_i18n_catalog()["locales"]
+
+        self.assertEqual(settings.LANGUAGE_CODE, catalog_locales["default"])
+        self.assertEqual(
+            [code for code, _ in settings.LANGUAGES],
+            catalog_locales["supported"],
+        )

realtime/broadcast.py

@@ -0,0 +1,35 @@
+from asgiref.sync import async_to_sync
+from channels.exceptions import InvalidChannelLayerError
+from channels.layers import get_channel_layer
+
+try:
+    from redis.exceptions import ConnectionError as RedisConnectionError
+except Exception:  # pragma: no cover - optional dependency in local/test runtimes
+    RedisConnectionError = RuntimeError
+
+
+async def broadcast_phase_event(session_code: str, event_type: str, payload: dict) -> None:
+    """Send a phase event to all WebSocket clients connected to a game session."""
+    try:
+        channel_layer = get_channel_layer()
+        if channel_layer is None:
+            return
+        group_name = f"game_{session_code.upper()}"
+        await channel_layer.group_send(
+            group_name,
+            {
+                "type": "phase.event",
+                "event_type": event_type,
+                "payload": payload,
+            },
+        )
+    except (InvalidChannelLayerError, RedisConnectionError):
+        return
+
+
+def sync_broadcast_phase_event(session_code: str, event_type: str, payload: dict) -> None:
+    """Sync wrapper for calling broadcast_phase_event from synchronous Django views."""
+    try:
+        async_to_sync(broadcast_phase_event)(session_code, event_type, payload)
+    except (InvalidChannelLayerError, RedisConnectionError):
+        return

realtime/consumers.py

@@ -0,0 +1,63 @@
+import json
+from urllib.parse import parse_qs
+
+from channels.generic.websocket import AsyncJsonWebsocketConsumer
+
+from fupogfakta.models import Player
+
+
+class GameConsumer(AsyncJsonWebsocketConsumer):
+    """
+    WebSocket consumer for a game session.
+
+    URL: ws/game/<session_code>/
+
+    Query params:
+      - session_token: player session token (players only)
+      - role=host: skip token check for host in MVP
+    """
+
+    async def connect(self):
+        self.session_code = self.scope["url_route"]["kwargs"]["session_code"].upper()
+        self.group_name = f"game_{self.session_code}"
+
+        query_string = self.scope.get("query_string", b"").decode()
+        params = parse_qs(query_string)
+
+        role = params.get("role", [None])[0]
+        session_token = params.get("session_token", [None])[0]
+
+        if role != "host":
+            if not session_token:
+                await self.close(code=4001)
+                return
+
+            try:
+                self.player = await Player.objects.aget(
+                    session_token=session_token,
+                    session__code=self.session_code,
+                )
+            except Player.DoesNotExist:
+                await self.close(code=4003)
+                return
+        else:
+            self.player = None
+
+        await self.channel_layer.group_add(self.group_name, self.channel_name)
+        await self.accept()
+
+    async def disconnect(self, close_code):
+        if hasattr(self, "group_name"):
+            await self.channel_layer.group_discard(self.group_name, self.channel_name)
+
+    async def receive_json(self, content, **kwargs):
+        if content.get("type") == "ping":
+            await self.send_json({"type": "pong"})
+
+    # --- Group message handlers ---
+
+    async def phase_event(self, event):
+        """Forward any phase_event broadcast to the WebSocket client."""
+        payload = dict(event.get("payload") or {})
+        payload["type"] = event["event_type"]
+        await self.send_json(payload)

realtime/routing.py

@@ -0,0 +1,7 @@
+from django.urls import re_path
+
+from . import consumers
+
+websocket_urlpatterns = [
+    re_path(r"^ws/game/(?P<session_code>[A-Z0-9]{4,8})/$", consumers.GameConsumer.as_asgi()),
+]

realtime/tests.py

@@ -1,3 +1,123 @@
-from django.test import TestCase
+import unittest
+from unittest.mock import AsyncMock, Mock, patch
 
-# Create your tests here.
+from channels.exceptions import InvalidChannelLayerError
+from django.contrib.auth import get_user_model
+from django.test import SimpleTestCase, TestCase
+
+try:
+    from channels.testing import WebsocketCommunicator
+except Exception:  # pragma: no cover - optional test dependency
+    WebsocketCommunicator = None
+
+from fupogfakta.models import GameSession, Player
+from partyhub.asgi import application
+from realtime.broadcast import broadcast_phase_event, sync_broadcast_phase_event
+from realtime.consumers import GameConsumer
+
+User = get_user_model()
+
+
+class BroadcastPhaseEventTests(SimpleTestCase):
+    @patch("realtime.broadcast.get_channel_layer", return_value=None)
+    async def test_broadcast_phase_event_noops_without_channel_layer(self, _mock_get_channel_layer):
+        await broadcast_phase_event("ABCD", "phase.scoreboard", {"phase": "scoreboard"})
+
+    @patch("realtime.broadcast.async_to_sync")
+    def test_sync_broadcast_phase_event_noops_when_channel_layer_is_unavailable(self, mock_async_to_sync):
+        mock_async_to_sync.return_value.side_effect = InvalidChannelLayerError("missing channel layer")
+
+        sync_broadcast_phase_event("ABCD", "phase.scoreboard", {"phase": "scoreboard"})
+
+    @patch("realtime.broadcast.async_to_sync")
+    def test_sync_broadcast_phase_event_still_broadcasts_when_channel_layer_exists(self, mock_async_to_sync):
+        sender = Mock()
+        mock_async_to_sync.return_value = sender
+
+        sync_broadcast_phase_event("ABCD", "phase.scoreboard", {"phase": "scoreboard"})
+
+        sender.assert_called_once_with("ABCD", "phase.scoreboard", {"phase": "scoreboard"})
+
+
+class GameConsumerPhaseEventTests(SimpleTestCase):
+    async def test_phase_event_restores_external_type_field(self):
+        consumer = GameConsumer()
+        consumer.send_json = AsyncMock()
+
+        await consumer.phase_event(
+            {
+                "event_type": "phase.test_event",
+                "payload": {"hello": "world"},
+            }
+        )
+
+        consumer.send_json.assert_awaited_once_with(
+            {
+                "type": "phase.test_event",
+                "hello": "world",
+            }
+        )
+
+
+@unittest.skipIf(WebsocketCommunicator is None, "channels.testing dependencies unavailable")
+class GameConsumerConnectTest(TestCase):
+    def setUp(self):
+        self.user = User.objects.create_user(username="host", password="pw")
+        self.session = GameSession.objects.create(host=self.user, code="AABBCC")
+        self.player = Player.objects.create(session=self.session, nickname="Tester")
+
+    async def test_player_connect_and_ping(self):
+        token = self.player.session_token
+        communicator = WebsocketCommunicator(
+            application,
+            f"/ws/game/AABBCC/?session_token={token}",
+        )
+        connected, _ = await communicator.connect()
+        self.assertTrue(connected)
+
+        await communicator.send_json_to({"type": "ping"})
+        response = await communicator.receive_json_from()
+        self.assertEqual(response["type"], "pong")
+
+        await communicator.disconnect()
+
+    async def test_connect_without_token_rejected(self):
+        communicator = WebsocketCommunicator(application, "/ws/game/AABBCC/")
+        connected, code = await communicator.connect()
+        self.assertFalse(connected)
+        self.assertEqual(code, 4001)
+
+    async def test_connect_invalid_token_rejected(self):
+        communicator = WebsocketCommunicator(
+            application,
+            "/ws/game/AABBCC/?session_token=invalid-token",
+        )
+        connected, code = await communicator.connect()
+        self.assertFalse(connected)
+        self.assertEqual(code, 4003)
+
+    async def test_host_connect_without_token(self):
+        communicator = WebsocketCommunicator(
+            application,
+            "/ws/game/AABBCC/?role=host",
+        )
+        connected, _ = await communicator.connect()
+        self.assertTrue(connected)
+        await communicator.disconnect()
+
+    async def test_broadcast_reaches_connected_client(self):
+        token = self.player.session_token
+        communicator = WebsocketCommunicator(
+            application,
+            f"/ws/game/AABBCC/?session_token={token}",
+        )
+        connected, _ = await communicator.connect()
+        self.assertTrue(connected)
+
+        await broadcast_phase_event("AABBCC", "phase.test_event", {"hello": "world"})
+
+        message = await communicator.receive_json_from(timeout=2)
+        self.assertEqual(message["type"], "phase.test_event")
+        self.assertEqual(message["hello"], "world")
+
+        await communicator.disconnect()

requirements.txt

@@ -1,5 +1,6 @@
 Django==6.0.2
 channels>=4.1,<5
 channels-redis>=4.2,<5
+daphne>=4.1,<5
 mysqlclient>=2.2,<3
 python-dotenv>=1.0,<2

scripts/build_i18n_parity_report.py

@@ -0,0 +1,214 @@
+#!/usr/bin/env python3
+"""Build the shared i18n parity artifact for MVP-critical Django/Angular keys."""
+
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import re
+from collections import defaultdict
+from pathlib import Path
+from typing import Any
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+CATALOG_PATH = REPO_ROOT / "shared" / "i18n" / "lobby.json"
+ARTIFACT_PATH = REPO_ROOT / "shared" / "i18n" / "artifacts" / "lobby-mvp-keyspace-parity-report.v1.json"
+DJANGO_VIEWS_PATH = REPO_ROOT / "lobby" / "views.py"
+FRONTEND_VERTICAL_SLICE_PATH = REPO_ROOT / "frontend" / "src" / "spa" / "vertical-slice.ts"
+ANGULAR_I18N_PATH = REPO_ROOT / "frontend" / "angular" / "src" / "app" / "lobby-i18n.ts"
+ANGULAR_HOST_PATH = REPO_ROOT / "frontend" / "angular" / "src" / "app" / "features" / "host" / "host-shell.component.ts"
+ANGULAR_PLAYER_PATH = REPO_ROOT / "frontend" / "angular" / "src" / "app" / "features" / "player" / "player-shell.component.ts"
+
+ARTIFACT_NAME = "shared.i18n.lobby.mvp_keyspace_parity_report"
+ARTIFACT_VERSION = "v1"
+
+
+class ParityError(RuntimeError):
+    pass
+
+
+def _read_text(path: Path) -> str:
+    return path.read_text(encoding="utf-8")
+
+
+def _load_catalog() -> dict[str, Any]:
+    return json.loads(_read_text(CATALOG_PATH))
+
+
+def _catalog_hash() -> str:
+    return hashlib.sha256(CATALOG_PATH.read_bytes()).hexdigest()
+
+
+def _sorted_unique(values: list[str]) -> list[str]:
+    return sorted({value for value in values})
+
+
+def _extract_matches(path: Path, pattern: str) -> list[str]:
+    return re.findall(pattern, _read_text(path), re.MULTILINE)
+
+
+def _resolve_frontend_ui_key(key: str) -> str:
+    if key.startswith("lobby.shell."):
+        return key.replace("lobby.shell.", "app.", 1)
+    if key.startswith("game.host."):
+        return key.replace("game.host.", "host.", 1)
+    if key.startswith("game.player."):
+        return key.replace("game.player.", "player.", 1)
+    return key
+
+
+def _has_nested_key(root: dict[str, Any], dotted_key: str) -> bool:
+    current: Any = root
+    for part in dotted_key.split("."):
+        if not isinstance(current, dict) or part not in current:
+            return False
+        current = current[part]
+    return isinstance(current, dict)
+
+
+def build_report() -> dict[str, Any]:
+    catalog = _load_catalog()
+    locales = list(catalog["locales"]["supported"])
+    frontend_errors: dict[str, Any] = catalog["frontend"]["errors"]
+    frontend_ui: dict[str, Any] = catalog["frontend"]["ui"]
+    backend_error_codes: dict[str, str] = catalog["backend"]["error_codes"]
+    backend_errors: dict[str, Any] = catalog["backend"]["errors"]
+    backend_to_frontend: dict[str, str] = catalog["contract"]["backend_to_frontend_error_keys"]
+
+    django_error_codes = _sorted_unique(
+        _extract_matches(DJANGO_VIEWS_PATH, r'ERROR_CODES\.get\("([a-z0-9_]+)"')
+    )
+    frontend_runtime_error_fallbacks = _sorted_unique(
+        _extract_matches(FRONTEND_VERTICAL_SLICE_PATH, r"lobbyMessageFromApiPayload\([^\n]+?'([a-z0-9_]+)'\)")
+        + _extract_matches(FRONTEND_VERTICAL_SLICE_PATH, r"lobbyMessage\('([a-z0-9_]+)'\)")
+    )
+    angular_copy_keys = _sorted_unique(
+        _extract_matches(ANGULAR_HOST_PATH, r"copy\('([A-Za-z0-9_\.]+)'\)")
+        + _extract_matches(ANGULAR_PLAYER_PATH, r"copy\('([A-Za-z0-9_\.]+)'\)")
+    )
+    angular_catalog_paths = [_resolve_frontend_ui_key(key) for key in angular_copy_keys]
+
+    missing_backend_codes = [code for code in django_error_codes if code not in backend_error_codes]
+    missing_backend_translations = [code for code in django_error_codes if code not in backend_errors]
+    missing_contract_mappings = [code for code in django_error_codes if code not in backend_to_frontend]
+    mapped_frontend_error_keys = _sorted_unique(
+        [backend_to_frontend[code] for code in django_error_codes if code in backend_to_frontend]
+    )
+    missing_frontend_error_keys = [key for key in mapped_frontend_error_keys if key not in frontend_errors]
+    missing_frontend_runtime_fallbacks = [key for key in frontend_runtime_error_fallbacks if key not in frontend_errors]
+    missing_angular_catalog_paths = [path for path in angular_catalog_paths if not _has_nested_key(frontend_ui, path)]
+
+    dead_contract_aliases = _sorted_unique([code for code in backend_to_frontend if code not in backend_error_codes])
+    many_to_one_mappings: dict[str, list[str]] = defaultdict(list)
+    for code in django_error_codes:
+        frontend_key = backend_to_frontend.get(code)
+        if frontend_key:
+            many_to_one_mappings[frontend_key].append(code)
+    many_to_one_mappings = {
+        frontend_key: sorted(codes)
+        for frontend_key, codes in sorted(many_to_one_mappings.items())
+        if len(codes) > 1
+    }
+
+    blocking_issues = {
+        "missing_backend_codes": missing_backend_codes,
+        "missing_backend_translations": missing_backend_translations,
+        "missing_contract_mappings": missing_contract_mappings,
+        "missing_frontend_error_keys": missing_frontend_error_keys,
+        "missing_frontend_runtime_fallbacks": missing_frontend_runtime_fallbacks,
+        "missing_angular_catalog_paths": missing_angular_catalog_paths,
+    }
+    status = "pass" if not any(blocking_issues.values()) else "fail"
+
+    follow_ups: list[dict[str, str]] = []
+    if dead_contract_aliases:
+        follow_ups.append(
+            {
+                "priority": "need-to-have",
+                "item": "Either add missing backend/error_codes + backend/errors entries for dead contract aliases or remove them from contract.backend_to_frontend_error_keys.",
+                "evidence": ", ".join(dead_contract_aliases),
+            }
+        )
+    if many_to_one_mappings:
+        follow_ups.append(
+            {
+                "priority": "nice-to-have",
+                "item": "Decide whether grouped backend codes should keep collapsing into one Angular fallback key or be split into more specific frontend error copy as UX matures.",
+                "evidence": "; ".join(
+                    f"{frontend_key} <= {', '.join(codes)}" for frontend_key, codes in many_to_one_mappings.items()
+                ),
+            }
+        )
+
+    return {
+        "artifact_name": ARTIFACT_NAME,
+        "artifact_version": ARTIFACT_VERSION,
+        "naming_version_rule": "Keep a stable artifact_name and append only explicit schema-major suffixes to the filename/version (v1, v2, ...). Update artifact_version only when the report shape changes; refresh content in-place for catalog/keyspace changes.",
+        "source_of_truth": {
+            "catalog": str(CATALOG_PATH.relative_to(REPO_ROOT)),
+            "catalog_sha256": _catalog_hash(),
+            "source_paths": [
+                str(path.relative_to(REPO_ROOT))
+                for path in [
+                    DJANGO_VIEWS_PATH,
+                    FRONTEND_VERTICAL_SLICE_PATH,
+                    ANGULAR_I18N_PATH,
+                    ANGULAR_HOST_PATH,
+                    ANGULAR_PLAYER_PATH,
+                ]
+            ],
+        },
+        "scope": {
+            "issue": 277,
+            "related_epic": 175,
+            "mvp_locales": locales,
+            "definition": "MVP-critical keys are the Django error codes emitted by lobby/views.py plus the Angular fallback/UI keys consumed by the host/player MVP shells.",
+        },
+        "parity": {
+            "status": status,
+            "django_backend_error_codes_used_by_mvp": django_error_codes,
+            "angular_frontend_error_fallback_keys_used_by_mvp": frontend_runtime_error_fallbacks,
+            "angular_ui_keys_used_by_mvp": angular_copy_keys,
+            "angular_ui_catalog_paths": angular_catalog_paths,
+            "backend_codes_mapped_to_frontend_error_keys": {code: backend_to_frontend[code] for code in django_error_codes if code in backend_to_frontend},
+            "unique_frontend_error_keys_reached_from_django": mapped_frontend_error_keys,
+            "blocking_issues": blocking_issues,
+            "follow_ups": follow_ups,
+        },
+    }
+
+
+def write_report() -> None:
+    report = build_report()
+    ARTIFACT_PATH.parent.mkdir(parents=True, exist_ok=True)
+    ARTIFACT_PATH.write_text(json.dumps(report, indent=2, ensure_ascii=False) + "\n", encoding="utf-8")
+
+
+def check_report() -> None:
+    report = build_report()
+    if not ARTIFACT_PATH.exists():
+        raise ParityError(f"artifact missing: {ARTIFACT_PATH}")
+    existing = json.loads(_read_text(ARTIFACT_PATH))
+    if existing != report:
+        raise ParityError("artifact out of date; run scripts/build_i18n_parity_report.py --write")
+    if report["parity"]["status"] != "pass":
+        raise ParityError(json.dumps(report["parity"]["blocking_issues"], indent=2))
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--write", action="store_true")
+    parser.add_argument("--check", action="store_true")
+    args = parser.parse_args()
+    if args.write:
+        write_report()
+    if args.check:
+        check_report()
+    if not args.write and not args.check:
+        print(json.dumps(build_report(), indent=2, ensure_ascii=False))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/check_i18n_drift.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""Read-only drift check for shared i18n key coverage.
+
+Compares `shared/i18n/key-manifest.json` against `shared/i18n/lobby.json` and
+fails fast when keyspaces drift between frontend/backend contract sections.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+import sys
+from typing import Any
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+CATALOG_PATH = REPO_ROOT / "shared" / "i18n" / "lobby.json"
+MANIFEST_PATH = REPO_ROOT / "shared" / "i18n" / "key-manifest.json"
+
+
+def _load_json(path: Path) -> dict[str, Any]:
+    with path.open("r", encoding="utf-8") as handle:
+        return json.load(handle)
+
+
+def _as_set(value: Any) -> set[str]:
+    if not isinstance(value, list):
+        return set()
+    return {str(item) for item in value}
+
+
+def _require_translations(
+    errors: dict[str, Any],
+    locales: set[str],
+    label: str,
+    failures: list[str],
+) -> None:
+    for key, translations in errors.items():
+        if not isinstance(translations, dict):
+            failures.append(f"{label}.{key} must be an object of locale->message")
+            continue
+
+        for locale in sorted(locales):
+            value = translations.get(locale)
+            if not isinstance(value, str) or not value.strip():
+                failures.append(f"{label}.{key} missing non-empty '{locale}' translation")
+
+
+def main() -> int:
+    catalog = _load_json(CATALOG_PATH)
+    manifest = _load_json(MANIFEST_PATH)
+
+    failures: list[str] = []
+
+    manifest_locales = _as_set(manifest.get("locales"))
+    catalog_locales = _as_set(catalog.get("locales", {}).get("supported"))
+    if manifest_locales != catalog_locales:
+        failures.append(
+            "locale set mismatch: "
+            f"manifest={sorted(manifest_locales)} catalog={sorted(catalog_locales)}"
+        )
+
+    frontend_manifest = _as_set(manifest.get("frontend_error_keys"))
+    frontend_catalog = set(catalog.get("frontend", {}).get("errors", {}).keys())
+    if frontend_manifest != frontend_catalog:
+        failures.append(
+            "frontend error key mismatch: "
+            f"manifest-only={sorted(frontend_manifest - frontend_catalog)} "
+            f"catalog-only={sorted(frontend_catalog - frontend_manifest)}"
+        )
+
+    backend_code_manifest = _as_set(manifest.get("backend_error_codes"))
+    backend_code_catalog = set(catalog.get("backend", {}).get("error_codes", {}).keys())
+    if backend_code_manifest != backend_code_catalog:
+        failures.append(
+            "backend error code mismatch: "
+            f"manifest-only={sorted(backend_code_manifest - backend_code_catalog)} "
+            f"catalog-only={sorted(backend_code_catalog - backend_code_manifest)}"
+        )
+
+    backend_key_manifest = _as_set(manifest.get("backend_error_keys"))
+    backend_key_catalog = set(catalog.get("backend", {}).get("errors", {}).keys())
+    if backend_key_manifest != backend_key_catalog:
+        failures.append(
+            "backend error key mismatch: "
+            f"manifest-only={sorted(backend_key_manifest - backend_key_catalog)} "
+            f"catalog-only={sorted(backend_key_catalog - backend_key_manifest)}"
+        )
+
+    backend_to_frontend = catalog.get("contract", {}).get("backend_to_frontend_error_keys", {})
+    if not isinstance(backend_to_frontend, dict):
+        failures.append("contract.backend_to_frontend_error_keys must be an object")
+        backend_to_frontend = {}
+
+    for code in sorted(backend_code_catalog):
+        frontend_key = backend_to_frontend.get(code)
+        if frontend_key is None:
+            failures.append(f"missing contract mapping for backend code '{code}'")
+            continue
+        if frontend_key not in frontend_catalog:
+            failures.append(
+                f"mapping for backend code '{code}' points to unknown frontend key '{frontend_key}'"
+            )
+
+    allowed_contract_only_codes = _as_set(manifest.get("allowed_contract_only_backend_codes"))
+    unknown_mapping_codes = set(backend_to_frontend.keys()) - backend_code_catalog
+    disallowed_unknown_mapping_codes = unknown_mapping_codes - allowed_contract_only_codes
+    if disallowed_unknown_mapping_codes:
+        failures.append(
+            "contract contains mappings for unknown backend codes: "
+            f"{sorted(disallowed_unknown_mapping_codes)}"
+        )
+
+    _require_translations(catalog.get("frontend", {}).get("errors", {}), manifest_locales, "frontend.errors", failures)
+    _require_translations(catalog.get("backend", {}).get("errors", {}), manifest_locales, "backend.errors", failures)
+
+    if failures:
+        print("i18n drift check FAILED")
+        for failure in failures:
+            print(f" - {failure}")
+        return 1
+
+    print("i18n drift check OK")
+    print(f" - locales: {sorted(manifest_locales)}")
+    print(f" - frontend error keys: {len(frontend_catalog)}")
+    print(f" - backend error codes: {len(backend_code_catalog)}")
+    print(f" - backend error keys: {len(backend_key_catalog)}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/check_i18n_parity_artifact.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+"""Guard issue #277 parity artifact against non-deterministic regeneration."""
+
+from __future__ import annotations
+
+import hashlib
+import subprocess
+import sys
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+ARTIFACT_PATH = REPO_ROOT / "docs" / "ISSUE-277-SHARED-I18N-PARITY-ARTIFACT.md"
+REPORT_SCRIPT = REPO_ROOT / "scripts" / "report_i18n_parity.py"
+
+
+def sha256(path: Path) -> str:
+    return hashlib.sha256(path.read_bytes()).hexdigest()
+
+
+def main() -> int:
+    before = sha256(ARTIFACT_PATH)
+
+    for run in range(1, 3):
+        subprocess.run([sys.executable, str(REPORT_SCRIPT)], cwd=REPO_ROOT, check=True)
+        after = sha256(ARTIFACT_PATH)
+        if after != before:
+            raise SystemExit(
+                f"issue #277 parity artifact is not deterministic after run {run}: {before} != {after}"
+            )
+
+    print(f"issue #277 parity artifact deterministic: {before}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/report_i18n_parity.py

@@ -0,0 +1,196 @@
+#!/usr/bin/env python3
+"""Generate issue #277 shared i18n parity artifact.
+
+Read-only report over the shared lobby i18n catalog, with focus on MVP-critical
+backend/frontend parity used by Django and Angular.
+"""
+
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+CATALOG_PATH = REPO_ROOT / "shared" / "i18n" / "lobby.json"
+OUTPUT_PATH = REPO_ROOT / "docs" / "ISSUE-277-SHARED-I18N-PARITY-ARTIFACT.md"
+ARTIFACT_ID = "issue-277-shared-i18n-parity-report"
+ARTIFACT_VERSION = "1.0"
+
+MVP_FRONTEND_UI_KEYS = [
+    "frontend.ui.host.title",
+    "frontend.ui.player.title",
+    "frontend.ui.common.session_code",
+    "frontend.ui.player.nickname",
+    "frontend.ui.player.join",
+    "frontend.ui.host.start_round",
+    "frontend.ui.host.show_question",
+    "frontend.ui.player.lie_label",
+    "frontend.ui.player.submit_lie",
+    "frontend.ui.player.submit_guess",
+    "frontend.ui.host.mix_answers",
+    "frontend.ui.host.calculate_scores",
+    "frontend.ui.host.load_scoreboard",
+    "frontend.ui.host.final_leaderboard",
+    "frontend.ui.player.final_leaderboard",
+    "frontend.ui.common.points_short",
+]
+
+MVP_FRONTEND_ERROR_KEYS = [
+    "frontend.errors.session_code_required",
+    "frontend.errors.session_not_found",
+    "frontend.errors.nickname_invalid",
+    "frontend.errors.nickname_taken",
+    "frontend.errors.join_failed",
+    "frontend.errors.start_round_failed",
+    "frontend.errors.unknown",
+]
+
+MVP_BACKEND_CODES = [
+    "backend.error_codes.session_code_required",
+    "backend.error_codes.nickname_invalid",
+    "backend.error_codes.session_not_found",
+    "backend.error_codes.session_not_joinable",
+    "backend.error_codes.nickname_taken",
+    "backend.error_codes.category_slug_required",
+    "backend.error_codes.category_not_found",
+    "backend.error_codes.round_start_invalid_phase",
+    "backend.error_codes.round_already_configured",
+]
+
+
+@dataclass(frozen=True)
+class MappingRow:
+    backend_code: str
+    backend_key: str
+    frontend_key: str
+    locales_ok: bool
+    parity_status: str
+    note: str
+
+
+def load_catalog() -> dict:
+    return json.loads(CATALOG_PATH.read_text(encoding="utf-8"))
+
+
+def get_path(data: dict, dotted: str):
+    node = data
+    for part in dotted.split("."):
+        node = node[part]
+    return node
+
+
+def translation_state(data: dict, dotted: str) -> tuple[bool, list[str]]:
+    translations = get_path(data, dotted)
+    missing = [locale for locale in ("en", "da") if not isinstance(translations.get(locale), str) or not translations[locale].strip()]
+    return (not missing, missing)
+
+
+def build_mapping_rows(catalog: dict) -> list[MappingRow]:
+    rows: list[MappingRow] = []
+    mapping = catalog["contract"]["backend_to_frontend_error_keys"]
+    backend_errors = catalog["backend"]["errors"]
+
+    for dotted_code in MVP_BACKEND_CODES:
+        code = dotted_code.removeprefix("backend.error_codes.")
+        backend_key = catalog["backend"]["error_codes"][code]
+        frontend_key = mapping[code]
+        backend_locales_ok, _ = translation_state(catalog, f"backend.errors.{backend_key}")
+        frontend_locales_ok, _ = translation_state(catalog, f"frontend.errors.{frontend_key}")
+        note = "1:1" if code == frontend_key else "many:1 collapse" if frontend_key == "start_round_failed" else "mapped alias"
+        rows.append(
+            MappingRow(
+                backend_code=code,
+                backend_key=backend_key,
+                frontend_key=frontend_key,
+                locales_ok=backend_locales_ok and frontend_locales_ok,
+                parity_status="aligned" if frontend_key in backend_errors or code == frontend_key else "mapped",
+                note=note,
+            )
+        )
+    return rows
+
+
+def render_report(catalog: dict) -> str:
+    mapping_rows = build_mapping_rows(catalog)
+    frontend_ui_ok = all(translation_state(catalog, key)[0] for key in MVP_FRONTEND_UI_KEYS)
+    frontend_error_ok = all(translation_state(catalog, key)[0] for key in MVP_FRONTEND_ERROR_KEYS)
+    backend_code_ok = all(translation_state(catalog, f"backend.errors.{catalog['backend']['error_codes'][key.removeprefix('backend.error_codes.')]}" )[0] for key in MVP_BACKEND_CODES)
+    mapped_frontend_keys = sorted({row.frontend_key for row in mapping_rows})
+    collapsed_codes = [row.backend_code for row in mapping_rows if row.frontend_key == "start_round_failed"]
+
+    lines: list[str] = []
+    lines.append("# ISSUE-277 Artifact — shared i18n registry parity report (Django ↔ Angular MVP)")
+    lines.append("")
+    lines.append("Issue: **#277** (`[READY][#175][P3] Shared i18n registry artifact: backend/frontend keyspace parity report`)")
+    lines.append("")
+    lines.append("## Artifact metadata")
+    lines.append("")
+    lines.append(f"- `artifact_id`: `{ARTIFACT_ID}`")
+    lines.append(f"- `artifact_version`: `{ARTIFACT_VERSION}`")
+    lines.append(f"- `catalog_source`: `{CATALOG_PATH.relative_to(REPO_ROOT)}`")
+    lines.append(f"- `generator`: `scripts/{Path(__file__).name}`")
+    lines.append("")
+    lines.append("## Naming/version rules (email-manager-inspired strategy)")
+    lines.append("")
+    lines.append("- **Single canonical artifact per issue**: issue-bundne rapporter navngives `docs/ISSUE-<nr>-<slug>-ARTIFACT.md`.")
+    lines.append("- **Stable artifact identity**: `artifact_id` ændres ikke ved tekstlige opdateringer i samme rapporttype; det er den faste reference i review/ops.")
+    lines.append("- **Explicit artifact versioning**: `artifact_version` bumpes, når rapportlogik eller scope ændres, så drift/review kan se forskel på format- vs. dataændringer.")
+    lines.append("- **Shared namespace first**: keys refereres med fulde navnerum (`frontend.ui.*`, `frontend.errors.*`, `backend.error_codes.*`, `backend.errors.*`) i stedet for lokale aliases i artefakter.")
+    lines.append("- **Source-of-truth before consumers**: rapporten afledes fra `shared/i18n/lobby.json`; Django/Angular beskrives som consumers af samme registry og ikke som parallelle kontrakter.")
+    lines.append("")
+    lines.append("## MVP-critical parity summary")
+    lines.append("")
+    lines.append(f"- Frontend UI gameplay keys checked: **{len(MVP_FRONTEND_UI_KEYS)}** → `{'OK' if frontend_ui_ok else 'DRIFT'}`")
+    lines.append(f"- Frontend error keys checked: **{len(MVP_FRONTEND_ERROR_KEYS)}** → `{'OK' if frontend_error_ok else 'DRIFT'}`")
+    lines.append(f"- Backend gameplay/error codes checked: **{len(MVP_BACKEND_CODES)}** → `{'OK' if backend_code_ok else 'DRIFT'}`")
+    lines.append(f"- Distinct frontend error keys reached from backend MVP flow: **{len(mapped_frontend_keys)}** (`{', '.join(mapped_frontend_keys)}`)")
+    lines.append("")
+    lines.append("Status: **Shared locale matrix is aligned (`en`, `da`) and backend→frontend error handling is contract-complete for MVP-critical flow.**")
+    lines.append("")
+    lines.append("## Django ↔ Angular parity matrix (MVP-critical error contract)")
+    lines.append("")
+    lines.append("| Backend code (`backend.error_codes.*`) | Django message key (`backend.errors.*`) | Angular key (`frontend.errors.*`) | Locales `en/da` | Parity note |")
+    lines.append("|---|---|---|---|---|")
+    for row in mapping_rows:
+        lines.append(
+            f"| `{row.backend_code}` | `{row.backend_key}` | `{row.frontend_key}` | `{'OK' if row.locales_ok else 'DRIFT'}` | {row.note} |"
+        )
+    lines.append("")
+    lines.append("## Scope notes")
+    lines.append("")
+    lines.append("- **Django** consumes backend codes/messages directly from `shared/i18n/lobby.json` via `lobby/i18n.py`.")
+    lines.append("- **Angular** consumes the same registry via `frontend/shared/i18n/lobby-loader.ts` and runtime helpers in `frontend/angular/src/app/lobby-i18n.ts`.")
+    lines.append("- **Parity in MVP** is therefore strongest on the shared error contract and locale matrix; gameplay UI labels are frontend-owned but still live in the same registry.")
+    lines.append("")
+    lines.append("## Verified MVP gameplay UI keyspace present in the shared registry")
+    lines.append("")
+    for key in MVP_FRONTEND_UI_KEYS:
+        lines.append(f"- `{key}`")
+    lines.append("")
+    lines.append("## Concrete deviations / follow-up items")
+    lines.append("")
+    lines.append(f"1. **Error granularity collapse remains intentional**: backend codes `{', '.join(collapsed_codes)}` all map to `frontend.errors.start_round_failed`. Follow-up only if product wants case-specific Angular copy instead of one shared host failure message.")
+    lines.append("2. **Frontend-only fallback copy is not mirrored in Django**: `frontend.errors.unknown` and `frontend.errors.session_fetch_failed` are Angular-side resilience keys, not backend contract keys. Follow-up if API responses should expose stable backend equivalents for these states.")
+    lines.append("3. **Gameplay UI labels are registry-shared but not backend-rendered**: `frontend.ui.host.*`, `frontend.ui.player.*`, and `frontend.ui.common.*` are available in the shared artifact, but Django currently consumes only the backend error slice. Follow-up only if server-rendered views must guarantee the same UI label surface as Angular.")
+    lines.append("")
+    lines.append("## Re-run")
+    lines.append("")
+    lines.append("```bash")
+    lines.append("python3 scripts/check_i18n_drift.py")
+    lines.append("python3 scripts/report_i18n_parity.py")
+    lines.append("python3 scripts/check_i18n_parity_artifact.py")
+    lines.append("```")
+    lines.append("")
+    return "\n".join(lines)
+
+
+def main() -> int:
+    catalog = load_catalog()
+    OUTPUT_PATH.write_text(render_report(catalog), encoding="utf-8")
+    print(OUTPUT_PATH.relative_to(REPO_ROOT))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

shared/i18n/artifacts/lobby-mvp-keyspace-parity-report.v1.json

@@ -0,0 +1,158 @@
+{
+  "artifact_name": "shared.i18n.lobby.mvp_keyspace_parity_report",
+  "artifact_version": "v1",
+  "naming_version_rule": "Keep a stable artifact_name and append only explicit schema-major suffixes to the filename/version (v1, v2, ...). Update artifact_version only when the report shape changes; refresh content in-place for catalog/keyspace changes.",
+  "source_of_truth": {
+    "catalog": "shared/i18n/lobby.json",
+    "catalog_sha256": "d9f7227bddd007f2c56f33dfd0015bcffb3b60c52dc756126a02b7e4de638adb",
+    "source_paths": [
+      "lobby/views.py",
+      "frontend/src/spa/vertical-slice.ts",
+      "frontend/angular/src/app/lobby-i18n.ts",
+      "frontend/angular/src/app/features/host/host-shell.component.ts",
+      "frontend/angular/src/app/features/player/player-shell.component.ts"
+    ]
+  },
+  "scope": {
+    "issue": 277,
+    "related_epic": 175,
+    "mvp_locales": [
+      "en",
+      "da"
+    ],
+    "definition": "MVP-critical keys are the Django error codes emitted by lobby/views.py plus the Angular fallback/UI keys consumed by the host/player MVP shells."
+  },
+  "parity": {
+    "status": "pass",
+    "django_backend_error_codes_used_by_mvp": [],
+    "angular_frontend_error_fallback_keys_used_by_mvp": [
+      "join_failed",
+      "session_code_required",
+      "session_fetch_failed",
+      "start_round_failed"
+    ],
+    "angular_ui_keys_used_by_mvp": [
+      "common.back_to_join",
+      "common.points_short",
+      "common.prompt",
+      "common.refresh",
+      "common.retry",
+      "common.round",
+      "common.round_question_id",
+      "common.session_code",
+      "common.status",
+      "common.unknown_error",
+      "host.audio_locale_hint",
+      "host.calculate_scores",
+      "host.category",
+      "host.final_leaderboard",
+      "host.finish_game",
+      "host.finish_game_failed",
+      "host.load_scoreboard",
+      "host.mix_answers",
+      "host.next_round_failed",
+      "host.retry_finish",
+      "host.retry_next_round",
+      "host.retry_scoreboard",
+      "host.scoreboard_failed",
+      "host.session_code_required",
+      "host.session_refresh_failed",
+      "host.show_question",
+      "host.start_next_round",
+      "host.start_round",
+      "host.title",
+      "host.winner",
+      "player.audio_policy_notice",
+      "player.final_leaderboard",
+      "player.guess_submit_failed",
+      "player.join",
+      "player.join_failed",
+      "player.lie_label",
+      "player.lie_submit_failed",
+      "player.loading_join",
+      "player.loading_refresh",
+      "player.loading_submit_guess",
+      "player.loading_submit_lie",
+      "player.nickname",
+      "player.offline_text",
+      "player.reconnecting_text",
+      "player.retry_guess_submit",
+      "player.retry_lie_submit",
+      "player.retry_now",
+      "player.session_refresh_failed",
+      "player.submit_guess",
+      "player.submit_lie",
+      "player.title"
+    ],
+    "angular_ui_catalog_paths": [
+      "common.back_to_join",
+      "common.points_short",
+      "common.prompt",
+      "common.refresh",
+      "common.retry",
+      "common.round",
+      "common.round_question_id",
+      "common.session_code",
+      "common.status",
+      "common.unknown_error",
+      "host.audio_locale_hint",
+      "host.calculate_scores",
+      "host.category",
+      "host.final_leaderboard",
+      "host.finish_game",
+      "host.finish_game_failed",
+      "host.load_scoreboard",
+      "host.mix_answers",
+      "host.next_round_failed",
+      "host.retry_finish",
+      "host.retry_next_round",
+      "host.retry_scoreboard",
+      "host.scoreboard_failed",
+      "host.session_code_required",
+      "host.session_refresh_failed",
+      "host.show_question",
+      "host.start_next_round",
+      "host.start_round",
+      "host.title",
+      "host.winner",
+      "player.audio_policy_notice",
+      "player.final_leaderboard",
+      "player.guess_submit_failed",
+      "player.join",
+      "player.join_failed",
+      "player.lie_label",
+      "player.lie_submit_failed",
+      "player.loading_join",
+      "player.loading_refresh",
+      "player.loading_submit_guess",
+      "player.loading_submit_lie",
+      "player.nickname",
+      "player.offline_text",
+      "player.reconnecting_text",
+      "player.retry_guess_submit",
+      "player.retry_lie_submit",
+      "player.retry_now",
+      "player.session_refresh_failed",
+      "player.submit_guess",
+      "player.submit_lie",
+      "player.title"
+    ],
+    "backend_codes_mapped_to_frontend_error_keys": {},
+    "unique_frontend_error_keys_reached_from_django": [],
+    "blocking_issues": {
+      "missing_backend_codes": [],
+      "missing_backend_translations": [],
+      "missing_contract_mappings": [],
+      "missing_frontend_error_keys": [],
+      "missing_frontend_runtime_fallbacks": [],
+      "missing_angular_catalog_paths": []
+    },
+    "follow_ups": [
+      {
+        "priority": "need-to-have",
+        "item": "Either add missing backend/error_codes + backend/errors entries for dead contract aliases or remove them from contract.backend_to_frontend_error_keys.",
+        "evidence": "host_only_action"
+      }
+    ]
+  }
+}