Mobile apps — Capacitor builds for Android and iOS, store submission

[MA1002643]

Context

Brief §4.3 via §4.5's phased plan: the PWA already delivers mobile installability; the Capacitor wrappers add store distribution and the native capabilities web-on-iOS withholds (robust background audio, full lock-screen control, reliable push). Same web bundle, parity by construction (§4.4).

Scope

• Capacitor 7 projects (Android/iOS) loading the production bundle with an offline-shell fallback; plugin set: native audio-session management (background playback, interruptions: calls/alarms/route changes incl. CarPlay/Android Auto basics deferred-documented), media-session bridge (lock screen/notification controls behind the existing adapter), push via APNs/FCM bridged to the notification model, secure storage (Keystore/Keychain) for sessions and offline-content keys (upgrading Offline downloads — encrypted local storage, quota management, reconnect sync #42's key wrapping on-device), deep links/universal links, share-sheet.
• iOS specifics: background-audio entitlement, Sign in with Apple review requirements (done in M5), ATT not needed (no tracking — verify), privacy manifest + nutrition labels from the GDPR data map.
• Android specifics: foreground-service playback with media notification, battery-optimisation guidance UX, target-SDK compliance.
• Store readiness: listings, screenshots, age ratings, content policies (user-generated content moderation requirements — met by the M8/M9 moderation features), review-guideline pass (payments not applicable yet), TestFlight/Internal-testing tracks, staged rollout.
• CI: reproducible signed builds (fastlane), version alignment with web releases.

Acceptance criteria

• Critical-flow + playback suites pass on real devices (the M6 device matrix) in wrapper builds; background/lock-screen playback robust across interruption tests.
• Offline downloads play in airplane mode on both platforms with keys held in hardware-backed storage (attestation checked where available).
• Push round-trip works on both platforms; deep links open correct in-app surfaces from cold start.
• Both apps accepted into Play Store (production, staged) and App Store; store metadata privacy declarations match the data map.

Technical notes

Store review is the schedule risk (§4.5 exists precisely for this) — submit early betas the moment playback works in-wrapper; keep the web product's release train fully independent throughout.

Dependencies

Depends on #41, #42, #29, #33, #45. Blocks #65.