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/blocs/trip/trip_event.dart

@@ -1,6 +1,26 @@
+/// Events for trip-related operations in the TripBloc.
+///
+/// This file defines all possible events that can be dispatched to the TripBloc
+/// to trigger trip-related state changes and operations such as loading trips,
+/// creating trips, updating trip information, and performing CRUD operations.
+///
+/// Event Categories:
+/// - **Loading Events**: LoadTripsByUserId
+/// - **CRUD Operations**: TripCreateRequested, TripUpdateRequested, TripDeleteRequested
+/// - **State Management**: ResetTrips
+///
+/// The events support complete trip lifecycle management with automatic
+/// list refreshing after operations to maintain UI consistency.
+///
+/// All events extend [TripEvent] and implement [Equatable] for proper
+/// equality comparison in the BLoC pattern.
 import 'package:equatable/equatable.dart';
 import '../../models/trip.dart';
 
+/// Base class for all trip-related events.
+///
+/// All trip events must extend this class and implement the [props] getter
+/// for proper equality comparison in the BLoC pattern.
 abstract class TripEvent extends Equatable {
   const TripEvent();
 
@@ -8,40 +28,98 @@ abstract class TripEvent extends Equatable {
   List<Object?> get props => [];
 }
 
+/// Event to load all trips associated with a specific user.
+///
+/// This event retrieves all trips where the user is a participant or organizer,
+/// providing a comprehensive view of the user's travel activities. The loading
+/// uses real-time streams to keep the trip list updated automatically.
+///
+/// Args:
+///   [userId]: The unique identifier of the user whose trips should be loaded
 class LoadTripsByUserId extends TripEvent {
+  /// The unique identifier of the user
   final String userId;
 
+  /// Creates a LoadTripsByUserId event.
+  ///
+  /// Args:
+  ///   [userId]: The user ID to load trips for
   const LoadTripsByUserId({required this.userId});
 
   @override
   List<Object?> get props => [userId];
 }
 
+/// Event to request creation of a new trip.
+///
+/// This event creates a new trip with the provided information and automatically
+/// refreshes the user's trip list to show the newly created trip. The operation
+/// includes validation and proper error handling.
+///
+/// Args:
+///   [trip]: The trip object containing all the trip information to create
 class TripCreateRequested extends TripEvent {
+  /// The trip object to create
   final Trip trip;
 
+  /// Creates a TripCreateRequested event.
+  ///
+  /// Args:
+  ///   [trip]: The trip object to create
   const TripCreateRequested({required this.trip});
 
   @override
   List<Object?> get props => [trip];
 }
 
+/// Event to request updating an existing trip.
+///
+/// This event updates an existing trip with new information and automatically
+/// refreshes the user's trip list to reflect the changes. The trip must have
+/// a valid ID for the update operation to succeed.
+///
+/// Args:
+///   [trip]: The trip object with updated information (must include valid ID)
 class TripUpdateRequested extends TripEvent {
+  /// The trip object with updated information
   final Trip trip;
 
+  /// Creates a TripUpdateRequested event.
+  ///
+  /// Args:
+  ///   [trip]: The updated trip object (must have valid ID)
   const TripUpdateRequested({required this.trip});
 
   @override
   List<Object?> get props => [trip];
 }
 
+/// Event to reset the trip state and clean up resources.
+///
+/// This event resets the TripBloc to its initial state, cancels any active
+/// stream subscriptions, and clears the current user context. This is typically
+/// used during user logout or when switching between different user contexts.
 class ResetTrips extends TripEvent {
+  /// Creates a ResetTrips event.
   const ResetTrips();
 }
 
+/// Event to request deletion of a trip.
+///
+/// This event permanently deletes a trip and all associated data including
+/// groups, expenses, and messages. This is a destructive operation that cannot
+/// be undone. The user's trip list is automatically refreshed after deletion.
+///
+/// Args:
+///   [tripId]: The unique identifier of the trip to delete
 class TripDeleteRequested extends TripEvent {
+  /// The unique identifier of the trip to delete
   final String tripId;
 
+  /// Creates a TripDeleteRequested event.
+  ///
+  /// Args:
+  ///   [tripId]: The ID of the trip to delete
   const TripDeleteRequested({required this.tripId});
 
   @override