feat(testflight): add beta app localization commands

- Implement `asc beta-app-localizations` CLI commands for list, get, create, update, and delete
- Support per-locale beta app descriptions, feedback email, marketing and privacy URLs
- Close parity gap with Apple's BetaAppLocalizations resource for TestFlight submissions

Author: hanrw

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **`asc beta-app-localizations {list,get,create,update,delete}` — TestFlight Beta App Description per locale** — closes the parity gap that blocked TestFlight submissions: Apple's `BetaAppLocalizations` resource holds the per-locale beta description, tester feedback email, marketing URL, and privacy policy URL shown in TestFlight before external testing can be enabled. Distinct from the existing `asc builds update-beta-notes` (which writes per-build "What to Test" notes) and `asc beta-review` (which writes review contact info). New `BetaAppLocalization` domain model + `@Mockable BetaAppLocalizationRepository` (Domain/Apps/TestFlight/), `SDKBetaAppLocalizationRepository` (Infrastructure) backed by `/v1/apps/{id}/betaAppLocalizations` (list), `/v1/betaAppLocalizations/{id}` (get/update/delete), and `/v1/betaAppLocalizations` (create). Affordances: `delete`, `get`, `listSiblings`, `update`. REST equivalents: `GET /api/v1/apps/:appId/beta-app-localizations` and `GET /api/v1/beta-app-localizations/:id` via `BetaAppLocalizationsController`. New REST path resolver entry for `beta-app-localizations` parented under `apps`. See `docs/features/beta-app-localizations.md`.
+
 ---
 
 ## [0.17.8] - 2026-04-29

README.md

@@ -53,7 +53,7 @@ Now `asc iap list --app-id <id>` enriches each IAP with the right submission aff
 | **Screenshots** | Create screenshot sets and upload images |
 | **App Previews** | Upload video previews (`.mp4`, `.mov`, `.m4v`) per locale and device size |
 | **App Shots** | AI-powered screenshot generation — single templates, gallery sets, plugin-provided themes (colors, decorations, animations), Gemini enhancement; two-step ThemeDesign workflow for batch styling without extra AI calls |
-| **TestFlight** | Manage beta groups; add/remove/import/export testers; submit builds for beta review |
+| **TestFlight** | Manage beta groups; add/remove/import/export testers; submit builds for beta review; per-locale **Beta App Description** + tester feedback metadata |
 | **Monetization** | IAPs (consumable, non-consumable, non-renewing); subscriptions, intro offers, **promotional offers**, **win-back offers**, offer codes (3-level), **promoted purchases**; full lifecycle (update/delete/unsubmit), per-territory pricing (with `proceedsYear2`), review screenshots, and 1024×1024 promotional images |
 | **Code Signing** | Bundle IDs, certificates, devices, provisioning profiles |
 | **Authentication** | Multi-account credential management; named accounts, active-account switching |
@@ -183,6 +183,12 @@ asc beta-review submissions get --submission-id <id>
 asc beta-review detail get --app-id <id>
 asc beta-review detail update --detail-id <id> [--contact-first-name <name>] [--notes <text>]
 
+asc beta-app-localizations list --app-id <id>
+asc beta-app-localizations get --localization-id <id>
+asc beta-app-localizations create --app-id <id> --locale en-US [--description <text>] [--feedback-email <email>] [--marketing-url <url>] [--privacy-policy-url <url>]
+asc beta-app-localizations update --localization-id <id> [--description <text>] [--feedback-email <email>]
+asc beta-app-localizations delete --localization-id <id>
+
 asc review-submissions list --app-id <id> [--state WAITING_FOR_REVIEW,IN_REVIEW,READY_FOR_REVIEW] [--limit 200]
 ```