[SC-03] app.json with iOS/Android config, permissions, LiveKit plugin, env vars (retry 1)

## SC-03: app.json with iOS/Android config, permissions, LiveKit plugin, env vars Section: Scaffold | Milestone: M1 | Owner: AG Lu ### Failing Tests - **bundle_id** (grep): Pattern `world\.onemarket\.c8audio` in `c8-audio/app.json` (need 1+ matches) - **mic_permission** (grep): Pattern `NSMicrophoneUsageDescription` in `c8-audio/app.json` (need 1+ matches) - **android_audio** (grep): Pattern `RECORD_AUDIO` in `c8-audio/app.json` (need 1+ matches) - **livekit_plugin** (grep): Pattern `livekit.*expo.*plugin` in `c8-audio/app.json` (need 1+ matches) - **background_audio** (grep): Pattern `UIBackgroundModes` in `c8-audio/app.json` (need 1+ matches) - **env_livekit_url** (grep): Pattern `LIVEKIT_URL` in `c8-audio/app.json` (need 1+ matches) ### Acceptance Criteria - File matching `c8-audio/app.json` must contain pattern `world\.onemarket\.c8audio` - File matching `c8-audio/app.json` must contain pattern `NSMicrophoneUsageDescription` - File matching `c8-audio/app.json` must contain pattern `RECORD_AUDIO` - File matching `c8-audio/app.json` must contain pattern `livekit.*expo.*plugin` - File matching `c8-audio/app.json` must contain pattern `UIBackgroundModes` - File matching `c8-audio/app.json` must contain pattern `LIVEKIT_URL` ### Codebase Conventions - Trilingual comments: // EN: ... // VI: ... // ES: ... - SPEC section refs in comments - Zod at module level with .safeParse() - (supabase as any) with eslint-disable - NextResponse.json() responses - Error format: { error: 'message' } ### Dependencies - SC-01: FAIL