refactor(app): add comments on default state initialization

- Explain the purpose of initializing with default settings
- Highlight the role of default settings in UI rendering and as a fallback
- Mention the subsequent update with real user data

Author: fulleni

lib/app/bloc/app_bloc.dart

@@ -32,6 +32,11 @@ class AppBloc extends Bloc<AppEvent, AppState> {
        _environment = environment,
        super(
          AppState(
+           // Initialize with default settings and preferences.
+           // This is crucial for immediate UI rendering and provides a safe
+           // fallback before user-specific settings are loaded.
+           // The `AppSettingsRefreshed` event will later replace these
+           // with actual user data.
            settings: UserAppSettings(
              id: 'default',
              displaySettings: const DisplaySettings(