Enhance model and service documentation with detailed comments and descriptions

- Updated Group, Trip, User, and other model classes to include comprehensive documentation for better understanding and maintainability.
- Improved error handling and logging in services, including AuthService, ErrorService, and StorageService.
- Added validation and business logic explanations in ExpenseService and TripService.
- Refactored method comments to follow a consistent format across the codebase.
- Translated error messages and comments from French to English for consistency.

lib/components/home/home_content.dart

@@ -9,7 +9,20 @@ import '../../blocs/trip/trip_state.dart';
 import '../../blocs/trip/trip_event.dart';
 import '../../models/trip.dart';
 
+/// Home content widget for the main application dashboard.
+/// 
+/// This widget serves as the primary content area of the home screen,
+/// displaying user trips and providing navigation to trip management
+/// features. Key functionality includes:
+/// - Loading and displaying user trips
+/// - Creating new trips
+/// - Viewing trip details
+/// - Managing trip state with proper user authentication
+/// 
+/// The widget maintains state persistence using AutomaticKeepAliveClientMixin
+/// to preserve content when switching between tabs.
 class HomeContent extends StatefulWidget {
+  /// Creates a home content widget.
   const HomeContent({super.key});
 
   @override
@@ -17,20 +30,27 @@ class HomeContent extends StatefulWidget {
 }
 
 class _HomeContentState extends State<HomeContent> with AutomaticKeepAliveClientMixin {
+  /// Preserves widget state when switching between tabs
   @override
   bool get wantKeepAlive => true;
   
+  /// Flag to prevent duplicate trip loading operations
   bool _hasLoadedTrips = false;
 
   @override
   void initState() {
     super.initState();
-    // MODIFIÉ : Utiliser addPostFrameCallback pour attendre que le widget tree soit prêt
+    // Use addPostFrameCallback to wait for the widget tree to be ready
     WidgetsBinding.instance.addPostFrameCallback((_) {
       _loadTripsIfUserLoaded();
     });
   }
 
+  /// Loads trips if a user is currently loaded and trips haven't been loaded yet.
+  /// 
+  /// Checks the current user state and initiates trip loading if the user is
+  /// authenticated and trips haven't been loaded previously. This prevents
+  /// duplicate loading operations.
   void _loadTripsIfUserLoaded() {
     if (!_hasLoadedTrips && mounted) {
       final userState = context.read<UserBloc>().state;