Refactor user and theme management to use BLoC pattern; remove provider classes and integrate new services for user and group functionalities

lib/blocs/user/user_state.dart

@@ -0,0 +1,61 @@
+import 'package:equatable/equatable.dart';
+
+abstract class UserState extends Equatable {
+  @override
+  List<Object?> get props => [];
+}
+
+class UserInitial extends UserState {}
+
+class UserLoading extends UserState {}
+
+class UserLoaded extends UserState {
+  final UserModel user;
+  
+  UserLoaded(this.user);
+  
+  @override
+  List<Object?> get props => [user];
+}
+
+class UserError extends UserState {
+  final String message;
+  
+  UserError(this.message);
+  
+  @override
+  List<Object?> get props => [message];
+}
+
+// Modèle utilisateur simple
+class UserModel {
+  final String id;
+  final String email;
+  final String prenom;
+  final String? nom;
+  
+  UserModel({
+    required this.id,
+    required this.email,
+    required this.prenom,
+    this.nom,
+  });
+  
+  factory UserModel.fromJson(Map<String, dynamic> json) {
+    return UserModel(
+      id: json['id'] ?? '',
+      email: json['email'] ?? '',
+      prenom: json['prenom'] ?? 'Voyageur',
+      nom: json['nom'],
+    );
+  }
+  
+  Map<String, dynamic> toJson() {
+    return {
+      'id': id,
+      'email': email,
+      'prenom': prenom,
+      'nom': nom,
+    };
+  }
+}