feat(mobile): implement centralized error handling and project cleanup

- Implemented centralized error handling system (#377)
- Unified UIErrorSnackbar and BlocErrorHandler mixin
- Migrated ClientAuthBloc and ClientHubsBloc
- Consolidated documentation
- Addresses Mobile Apps: Project Cleanup (#378)

apps/mobile/apps/client/lib/main.dart

@@ -22,6 +22,13 @@ void main() async {
   await Firebase.initializeApp(
     options: kIsWeb ? DefaultFirebaseOptions.currentPlatform : null,
   );
+  
+  // Register global BLoC observer for centralized error logging
+  Bloc.observer = CoreBlocObserver(
+    logEvents: true,
+    logStateChanges: false, // Set to true for verbose debugging
+  );
+  
   runApp(ModularApp(module: AppModule(), child: const AppWidget()));
 }
 

apps/mobile/apps/staff/lib/main.dart

@@ -16,6 +16,13 @@ void main() async {
   await Firebase.initializeApp(
     options: DefaultFirebaseOptions.currentPlatform,
   );
+  
+  // Register global BLoC observer for centralized error logging
+  Bloc.observer = CoreBlocObserver(
+    logEvents: true,
+    logStateChanges: false, // Set to true for verbose debugging
+  );
+  
   runApp(ModularApp(module: AppModule(), child: const AppWidget()));
 }