feat: Integrate Firebase Authentication and Firestore

- Added Firebase configuration to Android and iOS projects.
- Created `google-services.json` and `GoogleService-Info.plist` for Firebase setup.
- Implemented `AuthService` for handling user authentication with Firebase.
- Updated `UserProvider` to manage user data with Firestore.
- Refactored `ProfileContent`, `LoginPage`, and `SignUpPage` to use the new authentication service.
- Removed the old `UserService` and replaced it with Firestore-based user management.
- Added Firebase options in `firebase_options.dart` for platform-specific configurations.
- Updated dependencies in `pubspec.yaml` for Firebase packages.

lib/models/user.dart

@@ -5,14 +5,12 @@ class User {
   final String nom;
   final String prenom;
   final String email;
-  final String password;
 
   User({
     this.id,
     required this.nom,
     required this.prenom,
     required this.email,
-    required this.password,
   });
 
   // Constructeur pour créer un User depuis un Map (utile pour Firebase)
@@ -22,7 +20,6 @@ class User {
       nom: map['nom'] ?? '',
       prenom: map['prenom'] ?? '',
       email: map['email'] ?? '',
-      password: map['password'] ?? '',
     );
   }
 
@@ -39,7 +36,6 @@ class User {
       'nom': nom,
       'prenom': prenom,
       'email': email,
-      'password': password,
     };
   }
 
@@ -57,14 +53,12 @@ class User {
     String? nom,
     String? prenom,
     String? email,
-    String? password,
   }) {
     return User(
       id: id ?? this.id,
       nom: nom ?? this.nom,
       prenom: prenom ?? this.prenom,
       email: email ?? this.email,
-      password: password ?? this.password,
     );
   }
 
@@ -82,3 +76,4 @@ class User {
   @override
   int get hashCode => email.hashCode;
 }
+