ask-flutter-architect

<critical_constraints> ❌ NO global flutter command → use fvm flutter ❌ NO Riverpod/Bloc → project uses Streams+Provider ❌ NO Feature-First folders → use Layer-First ✅ MUST verify FVM version matches .fvmrc ✅ MUST run fvm flutter pub run build_runner build after model changes ✅ MUST use extensions from lib/components/Utils.dart </critical_constraints>

<fvm_protocol>

1. Check .fvmrc or .fvm/fvm_config.json
2. Run fvm flutter --version to verify
3. ALL commands: fvm flutter <command> </fvm_protocol>

<folder_structure> lib/ ├── api/ # Retrofit clients + models ├── components/ # Reusable UI widgets ├── screens/ # Screens by feature (tabs/, auth/, ...) ├── constants.dart # App-wide constants └── *Service.dart # Singleton business logic </folder_structure>

<state_management>

• Business logic: Singleton Services with StreamController.broadcast
• UI binding: StreamSubscription in StatefulWidget
• Provider: minimal, for root-level dependency injection only </state_management>

<api_pattern>

• Retrofit: lib/api/*_api.dart
• Models: lib/api/models/ with json_serializable
• Generation: fvm flutter pub run build_runner build </api_pattern>