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/pages/signup.dart

@@ -1,7 +1,8 @@
 import 'package:flutter/material.dart';
-import 'package:bcrypt/bcrypt.dart';
+import 'package:provider/provider.dart';
 import '../models/user.dart';
-import '../services/user_service.dart';
+import '../services/auth_service.dart';
+import '../providers/user_provider.dart';
 
 class SignUpPage extends StatefulWidget {
   const SignUpPage({super.key});
@@ -17,7 +18,7 @@ class _SignUpPageState extends State<SignUpPage> {
   final _emailController = TextEditingController();
   final _passwordController = TextEditingController();
   final _confirmPasswordController = TextEditingController();
-  final _userService = UserService();
+  final _authService = AuthService();
 
   bool _isLoading = false;
   bool _obscurePassword = true;
@@ -84,39 +85,29 @@ class _SignUpPageState extends State<SignUpPage> {
     });
 
     try {
-      // Vérifier si l'email existe déjà
-      bool emailExists = await _userService.emailExists(
-        _emailController.text.trim(),
-      );
-      if (emailExists) {
-        _showErrorDialog('Cet email est déjà utilisé');
-        return;
-      }
-
-      // Hasher le mot de passe
-      String hashedPassword = BCrypt.hashpw(
-        _passwordController.text,
-        BCrypt.gensalt(),
+      // Créer le compte avec Firebase Auth
+      final userCredential = await _authService.createAccount(
+        email: _emailController.text.trim(),
+        password: _passwordController.text,
       );
 
-      // Créer l'utilisateur
+      // Créer l'objet User
       User newUser = User(
+        id: userCredential.user!.uid,
         nom: _nomController.text.trim(),
         prenom: _prenomController.text.trim(),
-        email: _emailController.text.trim().toLowerCase(),
-        password: hashedPassword,
+        email: _emailController.text.trim(),
       );
 
-      // Sauvegarder l'utilisateur
-      bool success = await _userService.addUser(newUser);
+      // Sauvegarder les données utilisateur dans Firestore
+      await Provider.of<UserProvider>(context, listen: false).saveUserData(newUser);
 
-      if (success) {
-        _showSuccessDialog();
-      } else {
-        _showErrorDialog('Erreur lors de la création du compte');
-      }
+      // Mettre à jour le displayName
+      await _authService.updateDisplayName(displayName: newUser.fullName);
+
+      _showSuccessDialog();
     } catch (e) {
-      _showErrorDialog('Une erreur est survenue: ${e.toString()}');
+      _showErrorDialog('Erreur lors de la création du compte: ${e.toString()}');
     } finally {
       setState(() {
         _isLoading = false;
@@ -351,3 +342,4 @@ class _SignUpPageState extends State<SignUpPage> {
     );
   }
 }
+