weirsoe-party-protocol/docs/ISSUE-279-I18N-MVP-CLOSEOUT.md

# 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 på merge commit `e6ca18f` (`test: issue #278 da+en smoke gate and primary-only audio verification`, PR #285).
- Denne note er et snapshot af repo-tilstanden verificeret 2026-03-13 UTC, ikke en løbende garanti for senere `main`-ændringer.
- Åbne i18n-relaterede PR'er uden for `main`:
  - PR #282 `docs(#277): add shared i18n parity artifact` (`mergeable: true` ved verifikation)
  - PR #283 `feat(#275): harden django i18n locale negotiation and fallback` (`mergeable: true` ved verifikation)

## 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@e6ca18f` (reviewet 2026-03-13 UTC).

### 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`.
- [ ] Parity artifact fra issue #277 er ikke på `main` endnu (åben som PR #282, `mergeable: true` ved verifikation).

### 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`.
- [ ] Django i18n hardening fra issue #275 er ikke på `main` endnu (åben som PR #283, `mergeable: true` ved verifikation).
- [ ] PR #283 er stadig en separat release-afklaring, selv om den aktuelt er mergebar i Gitea.

### 4) Release gate before shipping i18n as “done”

- [ ] Merge eller afvis eksplicit PR #282, så parity-artifact-status er afklaret.
- [ ] Merge eller afvis eksplicit PR #283, så backend hardening-status er afklaret.
- [ ] 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 i praksis implementeret på `main`, og issue #279 kan levere den manglende release-/migration-closeout dokumentation uden nye kodeændringer i app-logikken.

Men hvis i18n-sporet skal kaldes fuldt release-ready, mangler der stadig en eksplicit beslutning om de to åbne opfølgnings-PR'er:
- **PR #282** (parity artifact)
- **PR #283** (Django i18n hardening, aktuelt ikke merge-ready)

Det betyder, at close-out-noten er komplet, men selve release-gaten bør betragte #282/#283 som åbne afklaringer, ikke som allerede landede leverancer.