fix(frontend): propagate locale changes reactively to mounted shells

2026-03-01 19:31:53 +00:00
33 changed files with 51 additions and 1579 deletions
--- a/docs/I18N_ARCHITECTURE.md
+++ b/docs/I18N_ARCHITECTURE.md
@@ -1,48 +0,0 @@
-# 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`
-
-Both Angular (`frontend/angular/src/app/lobby-i18n.ts`) and Django (`lobby/i18n.py`) read from this catalog.
-
-## 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`
--- a/docs/ISSUE-175-I18N-SHARED-CONTRACT-ARTIFACT.md
+++ b/docs/ISSUE-175-I18N-SHARED-CONTRACT-ARTIFACT.md
@@ -1,35 +0,0 @@
-# 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`).
--- a/docs/ISSUE-188-SPA-CUTOVER-HARDENING-ARTIFACT.md
+++ b/docs/ISSUE-188-SPA-CUTOVER-HARDENING-ARTIFACT.md
@@ -1,47 +0,0 @@
-# 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.
--- a/docs/ISSUE-200-SPA-HOST-PLAYER-PHASE-SYNC-ARTIFACT.md
+++ b/docs/ISSUE-200-SPA-HOST-PLAYER-PHASE-SYNC-ARTIFACT.md
@@ -1,57 +0,0 @@
-# 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**.
--- a/docs/ISSUE-207-I18N-AUDIO-SMOKE-ARTIFACT.md
+++ b/docs/ISSUE-207-I18N-AUDIO-SMOKE-ARTIFACT.md
@@ -1,35 +0,0 @@
-# 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`).
--- a/docs/ISSUE-223-PLAYER-AUDIO-GUARD-ARTIFACT.md
+++ b/docs/ISSUE-223-PLAYER-AUDIO-GUARD-ARTIFACT.md
@@ -1,20 +0,0 @@
-# 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).
--- a/docs/ISSUE-224-TRUNK-SEQUENCE-175.md
+++ b/docs/ISSUE-224-TRUNK-SEQUENCE-175.md
@@ -1,55 +0,0 @@
-# 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.
--- a/docs/ISSUE-226-SHARED-KEYMAP-LOCALE-CONTRACT.md
+++ b/docs/ISSUE-226-SHARED-KEYMAP-LOCALE-CONTRACT.md
@@ -1,30 +0,0 @@
-# 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`
--- a/docs/STAGING_GAMEPLAY_SMOKE_ARTIFACT.md
+++ b/docs/STAGING_GAMEPLAY_SMOKE_ARTIFACT.md
@@ -23,14 +23,11 @@ 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>
@@ -42,19 +39,6 @@ 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>
--- a/docs/UI_SMOKE.md
+++ b/docs/UI_SMOKE.md
@@ -20,29 +20,4 @@
 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.
--- a/docs/i18n-drift-check.md
+++ b/docs/i18n-drift-check.md
@@ -1,34 +0,0 @@
-# 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.
--- a/docs/i18n-keymap.md
+++ b/docs/i18n-keymap.md
@@ -1,69 +0,0 @@
-# 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`.
--- a/docs/spa-cutover-flag.md
+++ b/docs/spa-cutover-flag.md
@@ -12,53 +12,6 @@ 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.
-
 ## 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`
--- a/frontend/angular/src/app/features/host/host-shell.component.ts
+++ b/frontend/angular/src/app/features/host/host-shell.component.ts
@@ -55,7 +55,7 @@ type LeaderboardResponse = FinishGameResponse;
      <pre *ngIf="scoreboardPayload">{{ scoreboardPayload }}</pre>
      <div *ngIf="finalLeaderboard.length">
        <h3>{{ copy('host.final_leaderboard') }}</h3>
-        <p *ngIf="finalWinner"><strong>{{ copy('host.winner') }}:</strong> {{ finalWinner.nickname }} ({{ finalWinner.score }} {{ copy('common.points_short') }})</p>
+        <p *ngIf="finalWinner"><strong>{{ copy('host.winner') }}:</strong> {{ finalWinner.nickname }} ({{ finalWinner.score }} pts)</p>
        <ol>
          <li *ngFor="let entry of finalLeaderboard">{{ entry.nickname }}: {{ entry.score }}</li>
        </ol>
@@ -156,7 +156,7 @@ export class HostShellComponent implements OnInit, OnDestroy {
    try {
      const state = await this.controller.hydrateLobby(this.sessionCode);
      if (!state.session || state.errorMessage) {
-        throw new Error(state.errorMessage ?? this.copy('common.unknown_error'));
+        throw new Error(state.errorMessage ?? 'Unknown error');
      }
      this.session = state.session as SessionDetail;
      this.sessionCode = this.session.session.code;
@@ -177,7 +177,7 @@ export class HostShellComponent implements OnInit, OnDestroy {
    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 ?? this.copy('common.unknown_error'));
+        throw new Error(state.errorMessage ?? 'Unknown error');
      }
      this.session = state.session as SessionDetail;
      this.sessionCode = this.session.session.code;
--- a/frontend/angular/src/app/features/player/player-shell.component.spec.ts
+++ b/frontend/angular/src/app/features/player/player-shell.component.spec.ts
@@ -350,90 +350,4 @@ describe('PlayerShellComponent gameplay wiring', () => {

    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();
-
-    await expect(mediaPrototype.play()).resolves.toBeUndefined();
-
-    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');
-  });
 });
--- a/frontend/angular/src/app/features/player/player-shell.component.ts
+++ b/frontend/angular/src/app/features/player/player-shell.component.ts
@@ -16,19 +16,6 @@ interface SessionDetail {
 type ConnectionState = 'online' | 'reconnecting' | 'offline';
 type LoadingTransition = 'refresh' | 'join' | 'submit-lie' | 'submit-guess' | null;

-type MediaPrototypeWithGuardState = {
-  play?: () => Promise<void>;
-  __wppSecondaryDeviceAudioGuard__?: {
-    originalPlay: () => Promise<void>;
-    installs: number;
-  };
-};
-
-type GuardableMediaElement = {
-  muted?: boolean;
-  pause?: () => void;
-};
-
 function resolveLocalStorage(): Storage | undefined {
  if (typeof window === 'undefined') {
    return undefined;
@@ -126,7 +113,6 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
  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() {
    if (typeof navigator !== 'undefined' && !navigator.onLine) {
@@ -143,7 +129,6 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
    this.unsubscribeLocale = subscribeToLocaleChanges((locale) => {
      this.locale = locale;
    });
-    this.installSecondaryDeviceAudioGuard();

    const hashRoute = window.location.hash.replace(/^#\/?/, '');
    const match = hashRoute.match(/^player(?:\/[^/]+)?(?:\/([^/?#]+))?/i);
@@ -173,8 +158,6 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
    this.clearStateSyncTimer();
    this.unsubscribeLocale?.();
    this.unsubscribeLocale = null;
-    this.restoreAudioGuard?.();
-    this.restoreAudioGuard = null;
  }

  private readonly handleOnline = (): void => {
@@ -202,66 +185,6 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
    }
  }

-  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 = () => 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<GuardableMediaElement>
-      | GuardableMediaElement[]
-      | undefined;
-
-    if (!activeElements || typeof (activeElements as { forEach?: unknown }).forEach !== 'function') {
-      return;
-    }
-
-    activeElements.forEach((element) => {
-      element.muted = true;
-      element.pause?.();
-    });
-  }
-
  private scheduleStateSync(): void {
    this.clearStateSyncTimer();

@@ -309,7 +232,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
    if (error instanceof Error && error.message) {
      return error.message;
    }
-    return this.copy('common.unknown_error');
+    return 'Unknown error';
  }

  private markOnline(): void {
@@ -433,7 +356,7 @@ 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 ?? this.copy('common.unknown_error'));
+        throw new Error(state.errorMessage ?? 'Unknown error');
      }
      this.session = state.session as SessionDetail;
      this.sessionCode = this.session.session.code;
@@ -459,7 +382,7 @@ 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 ?? this.copy('common.unknown_error'));
+        throw new Error(state.errorMessage ?? 'Unknown error');
      }
      this.session = state.session as SessionDetail;
      this.sessionCode = this.session.session.code;
--- a/frontend/angular/src/app/gameplay-phase-machine.spec.ts
+++ b/frontend/angular/src/app/gameplay-phase-machine.spec.ts
@@ -1,96 +0,0 @@
-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,
-    });
-  });
-});
--- a/frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts
+++ b/frontend/angular/src/app/i18n-mvp-flow-smoke.spec.ts
@@ -1,61 +0,0 @@
-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';
-
-describe('i18n MVP flow smoke (host/player + audio policy)', () => {
-  afterEach(() => {
-    vi.restoreAllMocks();
-    vi.unstubAllGlobals();
-  });
-
-  it('resolves host/player copy in en and da from shared catalog', () => {
-    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(),
-    });
-    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
-
-    const host = new HostShellComponent();
-    const player = new PlayerShellComponent();
-    host.ngOnInit();
-    player.ngOnInit();
-
-    expect(host.copy('game.host.start_round')).toBe('Start round');
-    expect(player.copy('game.player.submit_guess')).toBe('Submit guess');
-
-    setPreferredLocale('da');
-
-    expect(host.copy('game.host.start_round')).toBe('Start runde');
-    expect(player.copy('game.player.submit_guess')).toBe('Send gæt');
-
-    player.ngOnDestroy();
-    host.ngOnDestroy();
-  });
-
-  it('keeps audio routing policy primary-only (client has no audio output)', () => {
-    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(),
-    });
-    vi.stubGlobal('navigator', { language: 'en-US', onLine: true });
-
-    const host = new HostShellComponent();
-    const player = new PlayerShellComponent();
-
-    expect(host.clientHasNoAudioOutput).toBe(true);
-    expect(player.clientHasNoAudioOutput).toBe(true);
-
-    player.ngOnDestroy();
-    host.ngOnDestroy();
-  });
-});
--- a/frontend/angular/src/app/lobby-i18n.spec.ts
+++ b/frontend/angular/src/app/lobby-i18n.spec.ts
@@ -44,94 +44,4 @@ describe('lobby i18n locale propagation', () => {
    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);
-  });
 });
--- a/frontend/angular/src/app/lobby-i18n.ts
+++ b/frontend/angular/src/app/lobby-i18n.ts
@@ -32,14 +32,11 @@ export function resolvePreferredLocale(): SupportedLocale {
    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);
+  activeLocale = normalizeLocale(queryLocale || storedLocale || browserLocale || DEFAULT_LOCALE);
  return activeLocale;
 }

@@ -65,23 +62,10 @@ export function subscribeToLocaleChanges(callback: (locale: SupportedLocale) =>
  };
 }

-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 {
  const normalizedLocale = normalizeLocale(locale);
  const fallbackLocale = DEFAULT_LOCALE;
-  const segments = resolveCatalogPath(key).split('.');
+  const segments = key.split('.');

  let cursor: unknown = lobbyCatalog.frontend.ui;
  for (const segment of segments) {
--- a/frontend/src/spa/gameplay-phase-machine.ts
+++ b/frontend/src/spa/gameplay-phase-machine.ts
@@ -46,7 +46,7 @@ export function deriveGameplayPhase(session: SessionDetailResponse | null): Game
    return null;
  }

-  if (status === 'lie' || status === 'guess' || status === 'reveal' || status === 'scoreboard') {
+  if (status === 'lie' || status === 'guess' || status === 'reveal') {
    return status;
  }

--- a/frontend/src/spa/lobby-i18n.ts
+++ b/frontend/src/spa/lobby-i18n.ts
@@ -1,55 +1,31 @@
 import lobbyCatalog from '../../../shared/i18n/lobby.json';

+type FrontendErrorKey = keyof typeof lobbyCatalog.frontend.errors;
+
 const frontendErrors = lobbyCatalog.frontend.errors;
-const localeConfig = lobbyCatalog.locales;
-const backendToFrontendErrorKeys = lobbyCatalog.contract.backend_to_frontend_error_keys as Record<string, keyof typeof frontendErrors>;

-type FrontendErrorKey = keyof typeof frontendErrors;
-type SupportedLocale = (typeof localeConfig.supported)[number];
+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'
+};

-function isFrontendErrorKey(value: string): value is FrontendErrorKey {
-  return value in frontendErrors;
+export function lobbyMessage(key: FrontendErrorKey): string {
+  return frontendErrors[key] ?? frontendErrors.unknown;
 }

-function normalizeLocale(rawLocale?: string): SupportedLocale {
-  const requested = (rawLocale ?? '').trim().toLowerCase();
-  if (localeConfig.supported.includes(requested as SupportedLocale)) {
-    return requested as SupportedLocale;
-  }
-  return localeConfig.default;
-}
-
-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[localeConfig.default]) {
-    return translations[localeConfig.default];
-  }
-
-  return key;
-}
-
-export function lobbyMessageFromApiPayload(payload: unknown, fallbackKey: FrontendErrorKey, locale?: string): string {
+export function lobbyMessageFromApiPayload(payload: unknown, fallbackKey: FrontendErrorKey): string {
  if (!payload || typeof payload !== 'object') {
-    return lobbyMessage(fallbackKey, locale);
+    return lobbyMessage(fallbackKey);
  }

  const record = payload as Record<string, unknown>;
  const code = typeof record.error_code === 'string' ? record.error_code : '';
-  const payloadLocale = typeof record.locale === 'string' ? record.locale : locale;
-  const mappedKey = code ? backendToFrontendErrorKeys[code] : undefined;
-
-  if (mappedKey && isFrontendErrorKey(mappedKey)) {
-    return lobbyMessage(mappedKey, payloadLocale);
+  const mappedKey = apiErrorMap[code];
+  if (!mappedKey) {
+    return lobbyMessage(fallbackKey);
  }

-  if (isFrontendErrorKey(code)) {
-    return lobbyMessage(code, payloadLocale);
-  }
-
-  return lobbyMessage(fallbackKey, payloadLocale);
+  return lobbyMessage(mappedKey);
 }
--- a/frontend/tests/lobby-i18n.contract.test.ts
+++ b/frontend/tests/lobby-i18n.contract.test.ts
@@ -1,68 +0,0 @@
-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.');
-  });
-});
--- a/lobby/i18n.py
+++ b/lobby/i18n.py
@@ -36,13 +36,7 @@ def lobby_i18n_error_messages() -> dict:

 def resolve_locale(request: HttpRequest) -> str:
    default_locale, supported_locales = i18n_locale_config()
-
-    raw_accept_language = (request.META.get("HTTP_ACCEPT_LANGUAGE") or "").split(",", 1)[0]
-    raw_requested = raw_accept_language.split(";", 1)[0].strip().replace("_", "-").split("-", 1)[0].lower()
-    if raw_requested in supported_locales:
-        return raw_requested
-
-    requested = (get_language_from_request(request) or "").replace("_", "-").split("-", 1)[0].lower()
+    requested = (get_language_from_request(request) or "").split("-", 1)[0].lower()
    if requested in supported_locales:
        return requested
    return default_locale
--- a/lobby/templates/lobby/player_screen.html
+++ b/lobby/templates/lobby/player_screen.html
@@ -89,8 +89,6 @@ 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");}
@@ -155,7 +153,6 @@ 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();
--- a/lobby/templates/lobby/spa_shell.html
+++ b/lobby/templates/lobby/spa_shell.html
@@ -1,13 +1,13 @@
 <!doctype html>
-<html lang="{{ shell_locale|default:'en' }}">
+<html lang="da">
 <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?v={{ spa_asset_version|urlencode }}">
+  <link rel="stylesheet" href="{{ spa_asset_base }}/styles.css">
 </head>
-<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 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>
 </html>
--- a/lobby/tests.py
+++ b/lobby/tests.py
@@ -2,7 +2,6 @@ import json
 import tempfile
 from datetime import timedelta
 from pathlib import Path
-from unittest.mock import patch

 from django.contrib.auth import get_user_model
 from django.core.management import call_command
@@ -20,7 +19,7 @@ from fupogfakta.models import (
    RoundConfig,
    RoundQuestion,
 )
-from lobby.i18n import i18n_locale_config, lobby_i18n_catalog, resolve_error_message, resolve_locale
+from lobby.i18n import resolve_error_message

 User = get_user_model()

@@ -209,8 +208,6 @@ class StartRoundTests(TestCase):
        )

        self.assertEqual(response.status_code, 403)
-        self.assertEqual(response.json()["error_code"], "host_only_start_round")
-        self.assertEqual(response.json()["locale"], "en")
        self.assertEqual(response.json()["error"], "Only host can start round")

    def test_start_round_requires_existing_active_category_with_questions(self):
@@ -230,8 +227,6 @@ class StartRoundTests(TestCase):
            content_type="application/json",
        )
        self.assertEqual(response.status_code, 400)
-        self.assertEqual(response.json()["error_code"], "category_has_no_questions")
-        self.assertEqual(response.json()["locale"], "en")
        self.assertEqual(response.json()["error"], "Category has no active questions")

    def test_start_round_rejects_non_lobby_session(self):
@@ -248,36 +243,6 @@ class StartRoundTests(TestCase):
        self.assertEqual(response.status_code, 400)
        self.assertEqual(response.json()["error"], "Round can only be started from lobby")

-    def test_start_round_error_localizes_to_danish(self):
-        self.client.login(username="other", password="secret123")
-
-        response = self.client.post(
-            reverse("lobby:start_round", kwargs={"code": self.session.code}),
-            data={"category_slug": self.category.slug},
-            content_type="application/json",
-            HTTP_ACCEPT_LANGUAGE="da",
-        )
-
-        self.assertEqual(response.status_code, 403)
-        self.assertEqual(response.json()["error_code"], "host_only_start_round")
-        self.assertEqual(response.json()["locale"], "da")
-        self.assertEqual(response.json()["error"], "Kun værten kan starte runden")
-
-    def test_start_round_error_falls_back_to_english_for_unsupported_locale(self):
-        self.client.login(username="other", password="secret123")
-
-        response = self.client.post(
-            reverse("lobby:start_round", kwargs={"code": self.session.code}),
-            data={"category_slug": self.category.slug},
-            content_type="application/json",
-            HTTP_ACCEPT_LANGUAGE="fr",
-        )
-
-        self.assertEqual(response.status_code, 403)
-        self.assertEqual(response.json()["error_code"], "host_only_start_round")
-        self.assertEqual(response.json()["locale"], "en")
-        self.assertEqual(response.json()["error"], "Only host can start round")
-

 class LieSubmissionTests(TestCase):
    def setUp(self):
@@ -468,8 +433,6 @@ class MixAnswersTests(TestCase):
        )

        self.assertEqual(response.status_code, 403)
-        self.assertEqual(response.json()["error_code"], "host_only_mix_answers")
-        self.assertEqual(response.json()["locale"], "en")
        self.assertEqual(response.json()["error"], "Only host can mix answers")

    def test_mix_answers_deduplicates_case_insensitive_lies(self):
@@ -1035,10 +998,6 @@ class UiScreenTests(TestCase):
        self.assertContains(response, "clearPlayerShellFatalError")
        self.assertContains(response, "updatePlayerShellErrorBoundary")
        self.assertContains(response, "player_shell_runtime_error")
-        self.assertContains(response, "installSecondaryDeviceAudioGuard")
-        self.assertContains(response, "silencePlayerMediaElements")
-        self.assertContains(response, "querySelectorAll(\"audio,video\")")
-        self.assertNotContains(response, "<audio")
        self.assertContains(response, "window.addEventListener(\"error\"")

    @override_settings(USE_SPA_UI=False)
@@ -1063,8 +1022,7 @@ class UiScreenTests(TestCase):
        self.assertContains(response, "<app-root")
        self.assertContains(response, "data-wpp-shell-route=\"/host\"")
        self.assertContains(response, "data-wpp-shell-kind=\"host\"")
-        self.assertContains(response, "/static/frontend/angular/browser/main.js?v=dev")
-        self.assertContains(response, "/static/frontend/angular/browser/styles.css?v=dev")
+        self.assertContains(response, "/static/frontend/angular/browser/main.js")

    @override_settings(USE_SPA_UI=True)
    def test_host_screen_deeplink_preserves_spa_path_when_feature_flag_enabled(self):
@@ -1098,17 +1056,7 @@ class UiScreenTests(TestCase):
        self.assertContains(response, "<app-root")
        self.assertContains(response, "data-wpp-shell-route=\"/player\"")
        self.assertContains(response, "data-wpp-shell-kind=\"player\"")
-        self.assertContains(response, "/static/frontend/angular/browser/main.js?v=dev")
-
-    @override_settings(USE_SPA_UI=True, WPP_SPA_ASSET_VERSION="release-2026-03-01")
-    def test_spa_shell_uses_configured_asset_version_for_cache_busting(self):
-        self.client.login(username="host_ui", password="secret123")
-
-        response = self.client.get(reverse("lobby:host_screen"))
-
-        self.assertEqual(response.status_code, 200)
-        self.assertContains(response, "/static/frontend/angular/browser/styles.css?v=release-2026-03-01")
-        self.assertContains(response, "/static/frontend/angular/browser/main.js?v=release-2026-03-01")
+        self.assertContains(response, "/static/frontend/angular/browser/main.js")


 class SessionDetailRoundQuestionTests(TestCase):
@@ -1256,82 +1204,5 @@ class SmokeStagingCommandTests(TestCase):


 class I18nResolverTests(TestCase):
-    def test_resolve_locale_accepts_language_tags_and_normalizes_to_supported_base_locale(self):
-        response = self.client.post(
-            reverse("lobby:join_session"),
-            data={"code": "", "nickname": "Luna"},
-            content_type="application/json",
-            HTTP_ACCEPT_LANGUAGE="da-DK,da;q=0.9,en;q=0.8",
-        )
-
-        self.assertEqual(response.status_code, 400)
-        self.assertEqual(resolve_locale(response.wsgi_request), "da")
-
-    def test_resolve_locale_accepts_underscore_language_tags(self):
-        response = self.client.post(
-            reverse("lobby:join_session"),
-            data={"code": "", "nickname": "Luna"},
-            content_type="application/json",
-            HTTP_ACCEPT_LANGUAGE="da_DK",
-        )
-
-        self.assertEqual(response.status_code, 400)
-        self.assertEqual(resolve_locale(response.wsgi_request), "da")
-
-    def test_resolve_locale_defaults_to_en_when_header_missing(self):
-        response = self.client.post(
-            reverse("lobby:join_session"),
-            data={"code": "", "nickname": "Luna"},
-            content_type="application/json",
-        )
-
-        self.assertEqual(response.status_code, 400)
-        self.assertEqual(resolve_locale(response.wsgi_request), "en")
-
    def test_missing_backend_key_returns_key_deterministically(self):
        self.assertEqual(resolve_error_message(key="missing_key", locale="da"), "missing_key")
-
-    def test_missing_backend_key_is_logged_with_context(self):
-        with self.assertLogs("lobby.i18n", level="WARNING") as logs:
-            result = resolve_error_message(key="missing_key", locale="da")
-
-        self.assertEqual(result, "missing_key")
-        self.assertTrue(any("i18n key missing in shared catalog" in entry for entry in logs.output))
-
-    def test_missing_locale_translation_falls_back_to_default_locale(self):
-        with patch(
-            "lobby.i18n.lobby_i18n_error_messages",
-            return_value={"session_code_required": {"en": "Session code is required"}},
-        ):
-            self.assertEqual(
-                resolve_error_message(key="session_code_required", locale="da"),
-                "Session code is required",
-            )
-
-    def test_shared_catalog_uses_en_default_and_da_en_matrix(self):
-        default_locale, supported_locales = i18n_locale_config()
-        catalog = lobby_i18n_catalog()
-
-        self.assertEqual(default_locale, "en")
-        self.assertIn("en", supported_locales)
-        self.assertIn("da", supported_locales)
-
-        for key, translations in catalog["backend"]["errors"].items():
-            self.assertTrue(translations.get("en"), f"backend key {key} missing en")
-            self.assertTrue(translations.get("da"), f"backend key {key} missing da")
-
-        for key, translations in catalog["frontend"]["errors"].items():
-            self.assertTrue(translations.get("en"), f"frontend key {key} missing en")
-            self.assertTrue(translations.get("da"), f"frontend key {key} missing da")
-
-    def test_backend_error_codes_map_via_shared_backend_frontend_key_map(self):
-        catalog = lobby_i18n_catalog()
-        backend_errors = catalog["backend"]["errors"]
-        frontend_errors = catalog["frontend"]["errors"]
-        shared_map = catalog["contract"]["backend_to_frontend_error_keys"]
-
-        for code, backend_key in catalog["backend"]["error_codes"].items():
-            frontend_key = shared_map.get(code)
-            self.assertIn(backend_key, backend_errors)
-            self.assertTrue(frontend_key, f"missing frontend mapping for backend code: {code}")
-            self.assertIn(frontend_key, frontend_errors)
--- a/lobby/ui_views.py
+++ b/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, resolve_locale
+from .i18n import lobby_i18n_catalog


 def _render_spa_shell(request, shell_route: str, shell_kind: str):
@@ -16,9 +16,7 @@ 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),
        },
    )

--- a/lobby/views.py
+++ b/lobby/views.py
@@ -268,11 +268,7 @@ def start_round(request: HttpRequest, code: str) -> JsonResponse:
        )

    if session.host_id != request.user.id:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("host_only_start_round", "host_only_start_round"),
-            status=403,
-        )
+        return JsonResponse({"error": "Only host can start round"}, status=403)

    if session.status != GameSession.Status.LOBBY:
        return api_error(
@@ -291,11 +287,7 @@ def start_round(request: HttpRequest, code: str) -> JsonResponse:
        )

    if not Question.objects.filter(category=category, is_active=True).exists():
-        return api_error(
-            request,
-            key=ERROR_CODES.get("category_has_no_questions", "category_has_no_questions"),
-            status=400,
-        )
+        return JsonResponse({"error": "Category has no active questions"}, status=400)

    with transaction.atomic():
        session = GameSession.objects.select_for_update().get(pk=session.pk)
@@ -348,41 +340,21 @@ def show_question(request: HttpRequest, code: str) -> JsonResponse:
    try:
        session = GameSession.objects.get(code=session_code)
    except GameSession.DoesNotExist:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("session_not_found", "session_not_found"),
-            status=404,
-        )
+        return JsonResponse({"error": "Session not found"}, status=404)

    if session.host_id != request.user.id:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("host_only_show_question", "host_only_show_question"),
-            status=403,
-        )
+        return JsonResponse({"error": "Only host can show question"}, status=403)

    if session.status != GameSession.Status.LIE:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("show_question_invalid_phase", "show_question_invalid_phase"),
-            status=400,
-        )
+        return JsonResponse({"error": "Question can only be shown in lie phase"}, status=400)

    try:
        round_config = RoundConfig.objects.get(session=session, number=session.current_round)
    except RoundConfig.DoesNotExist:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("round_config_missing", "round_config_missing"),
-            status=400,
-        )
+        return JsonResponse({"error": "Round config missing"}, status=400)

    if RoundQuestion.objects.filter(session=session, round_number=session.current_round).exists():
-        return api_error(
-            request,
-            key=ERROR_CODES.get("question_already_shown", "question_already_shown"),
-            status=409,
-        )
+        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(
@@ -391,11 +363,7 @@ def show_question(request: HttpRequest, code: str) -> JsonResponse:
    ).exclude(pk__in=used_question_ids)

    if not available_questions.exists():
-        return api_error(
-            request,
-            key=ERROR_CODES.get("no_available_questions", "no_available_questions"),
-            status=400,
-        )
+        return JsonResponse({"error": "No available questions in category"}, status=400)

    question = random.choice(list(available_questions))
    round_question = RoundQuestion.objects.create(
@@ -505,25 +473,13 @@ def mix_answers(request: HttpRequest, code: str, round_question_id: int) -> Json
    try:
        session = GameSession.objects.get(code=session_code)
    except GameSession.DoesNotExist:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("session_not_found", "session_not_found"),
-            status=404,
-        )
+        return JsonResponse({"error": "Session not found"}, status=404)

    if session.host_id != request.user.id:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("host_only_mix_answers", "host_only_mix_answers"),
-            status=403,
-        )
+        return JsonResponse({"error": "Only host can mix answers"}, status=403)

    if session.status not in {GameSession.Status.LIE, GameSession.Status.GUESS}:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("mix_answers_invalid_phase", "mix_answers_invalid_phase"),
-            status=400,
-        )
+        return JsonResponse({"error": "Answers can only be mixed in lie or guess phase"}, status=400)

    try:
        round_question = RoundQuestion.objects.get(
@@ -532,20 +488,12 @@ def mix_answers(request: HttpRequest, code: str, round_question_id: int) -> Json
            round_number=session.current_round,
        )
    except RoundQuestion.DoesNotExist:
-        return api_error(
-            request,
-            key=ERROR_CODES.get("round_question_not_found", "round_question_not_found"),
-            status=404,
-        )
+        return JsonResponse({"error": "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 api_error(
-                request,
-                key=ERROR_CODES.get("mix_answers_invalid_phase", "mix_answers_invalid_phase"),
-                status=400,
-            )
+            return JsonResponse({"error": "Answers can only be mixed in lie or guess phase"}, status=400)

        locked_round_question = RoundQuestion.objects.select_for_update().get(pk=round_question.pk)

@@ -561,11 +509,7 @@ def mix_answers(request: HttpRequest, code: str, round_question_id: int) -> Json
                deduped_answers.append(text.strip())

            if len(deduped_answers) < 2:
-                return api_error(
-                    request,
-                    key=ERROR_CODES.get("not_enough_answers_to_mix", "not_enough_answers_to_mix"),
-                    status=400,
-                )
+                return JsonResponse({"error": "Not enough answers to mix"}, status=400)

            random.shuffle(deduped_answers)
            locked_round_question.mixed_answers = deduped_answers
--- a/partyhub/settings.py
+++ b/partyhub/settings.py
@@ -111,9 +111,6 @@ 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'))
--- a/scripts/check_i18n_drift.py
+++ b/scripts/check_i18n_drift.py
@@ -1,132 +0,0 @@
-#!/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())
--- a/shared/i18n/key-manifest.json
+++ b/shared/i18n/key-manifest.json
@@ -1,60 +0,0 @@
-{
-  "locales": ["en", "da"],
-  "frontend_error_keys": [
-    "join_failed",
-    "nickname_invalid",
-    "nickname_taken",
-    "session_code_required",
-    "session_fetch_failed",
-    "session_not_found",
-    "start_round_failed",
-    "unknown"
-  ],
-  "backend_error_codes": [
-    "category_has_no_questions",
-    "category_not_found",
-    "category_slug_required",
-    "host_only_mix_answers",
-    "host_only_show_question",
-    "host_only_start_round",
-    "mix_answers_invalid_phase",
-    "nickname_invalid",
-    "nickname_taken",
-    "no_available_questions",
-    "not_enough_answers_to_mix",
-    "question_already_shown",
-    "round_already_configured",
-    "round_config_missing",
-    "round_question_not_found",
-    "round_start_invalid_phase",
-    "session_code_required",
-    "session_not_found",
-    "session_not_joinable",
-    "show_question_invalid_phase"
-  ],
-  "allowed_contract_only_backend_codes": [
-    "host_only_action"
-  ],
-  "backend_error_keys": [
-    "category_has_no_questions",
-    "category_not_found",
-    "category_slug_required",
-    "host_only_mix_answers",
-    "host_only_show_question",
-    "host_only_start_round",
-    "mix_answers_invalid_phase",
-    "nickname_invalid",
-    "nickname_taken",
-    "no_available_questions",
-    "not_enough_answers_to_mix",
-    "question_already_shown",
-    "round_already_configured",
-    "round_config_missing",
-    "round_question_not_found",
-    "round_start_invalid_phase",
-    "session_code_required",
-    "session_not_found",
-    "session_not_joinable",
-    "show_question_invalid_phase"
-  ]
-}
--- a/shared/i18n/lobby.json
+++ b/shared/i18n/lobby.json
@@ -74,14 +74,6 @@
        "round": {
          "en": "round",
          "da": "runde"
-        },
-        "points_short": {
-          "en": "pts",
-          "da": "point"
-        },
-        "unknown_error": {
-          "en": "Unknown error",
-          "da": "Ukendt fejl"
        }
      },
      "app": {
@@ -281,18 +273,7 @@
      "category_slug_required": "category_slug_required",
      "category_not_found": "category_not_found",
      "round_start_invalid_phase": "round_start_invalid_phase",
-      "round_already_configured": "round_already_configured",
-      "category_has_no_questions": "category_has_no_questions",
-      "show_question_invalid_phase": "show_question_invalid_phase",
-      "round_config_missing": "round_config_missing",
-      "question_already_shown": "question_already_shown",
-      "no_available_questions": "no_available_questions",
-      "mix_answers_invalid_phase": "mix_answers_invalid_phase",
-      "round_question_not_found": "round_question_not_found",
-      "not_enough_answers_to_mix": "not_enough_answers_to_mix",
-      "host_only_start_round": "host_only_start_round",
-      "host_only_show_question": "host_only_show_question",
-      "host_only_mix_answers": "host_only_mix_answers"
+      "round_already_configured": "round_already_configured"
    },
    "errors": {
      "session_code_required": {
@@ -330,89 +311,7 @@
      "round_already_configured": {
        "en": "Round already configured",
        "da": "Runden er allerede konfigureret"
-      },
-      "category_has_no_questions": {
-        "en": "Category has no active questions",
-        "da": "Kategorien har ingen aktive spørgsmål"
-      },
-      "show_question_invalid_phase": {
-        "en": "Question can only be shown in lie phase",
-        "da": "Spørgsmålet kan kun vises i løgnefasen"
-      },
-      "round_config_missing": {
-        "en": "Round config missing",
-        "da": "Rundekonfiguration mangler"
-      },
-      "question_already_shown": {
-        "en": "Question already shown for this round",
-        "da": "Spørgsmålet er allerede vist for denne runde"
-      },
-      "no_available_questions": {
-        "en": "No available questions in category",
-        "da": "Ingen tilgængelige spørgsmål i kategorien"
-      },
-      "mix_answers_invalid_phase": {
-        "en": "Answers can only be mixed in lie or guess phase",
-        "da": "Svar kan kun blandes i løgne- eller gættefasen"
-      },
-      "round_question_not_found": {
-        "en": "Round question not found",
-        "da": "Rundespørgsmål blev ikke fundet"
-      },
-      "not_enough_answers_to_mix": {
-        "en": "Not enough answers to mix",
-        "da": "Ikke nok svar at blande"
-      },
-      "host_only_start_round": {
-        "en": "Only host can start round",
-        "da": "Kun værten kan starte runden"
-      },
-      "host_only_show_question": {
-        "en": "Only host can show question",
-        "da": "Kun værten kan vise spørgsmålet"
-      },
-      "host_only_mix_answers": {
-        "en": "Only host can mix answers",
-        "da": "Kun værten kan blande svar"
      }
    }
-  },
-  "contract": {
-    "ownership": {
-      "artifact": "shared/i18n/lobby.json",
-      "backend": "lobby/* reads backend/errors + backend/error_codes",
-      "frontend": "frontend/* reads frontend/errors + frontend/ui + contract/backend_to_frontend_error_keys"
-    },
-    "locale": {
-      "default": "en",
-      "supported": [
-        "en",
-        "da"
-      ],
-      "fallback": "Use default locale when requested locale is unsupported or key translation is missing."
-    },
-    "backend_to_frontend_error_keys": {
-      "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",
-      "host_only_start_round": "start_round_failed",
-      "host_only_show_question": "start_round_failed",
-      "host_only_mix_answers": "start_round_failed",
-      "host_only_action": "start_round_failed",
-      "category_has_no_questions": "start_round_failed",
-      "show_question_invalid_phase": "start_round_failed",
-      "round_config_missing": "start_round_failed",
-      "question_already_shown": "start_round_failed",
-      "no_available_questions": "start_round_failed",
-      "mix_answers_invalid_phase": "start_round_failed",
-      "round_question_not_found": "start_round_failed",
-      "not_enough_answers_to_mix": "start_round_failed"
-    }
  }
 }