fix(chat): Correction race condition + Implémentation TODOs

## Corrections Critiques

### Race Condition - Statuts de Messages
- Fix : Les icônes de statut (✓, ✓✓, ✓✓ bleu) ne s'affichaient pas
- Cause : WebSocket delivery confirmations arrivaient avant messages locaux
- Solution : Pattern Optimistic UI dans chat_bloc.dart
  - Création message temporaire immédiate
  - Ajout à la liste AVANT requête HTTP
  - Remplacement par message serveur à la réponse
- Fichier : lib/presentation/state_management/chat_bloc.dart

## Implémentation TODOs (13/21)

### Social (social_header_widget.dart)
- ✅ Copier lien du post dans presse-papiers
- ✅ Partage natif via Share.share()
- ✅ Dialogue de signalement avec 5 raisons

### Partage (share_post_dialog.dart)
- ✅ Interface sélection d'amis avec checkboxes
- ✅ Partage externe via Share API

### Média (media_upload_service.dart)
- ✅ Parsing JSON réponse backend
- ✅ Méthode deleteMedia() pour suppression
- ✅ Génération miniature vidéo

### Posts (create_post_dialog.dart, edit_post_dialog.dart)
- ✅ Extraction URL depuis uploads
- ✅ Documentation chargement médias

### Chat (conversations_screen.dart)
- ✅ Navigation vers notifications
- ✅ ConversationSearchDelegate pour recherche

## Nouveaux Fichiers

### Configuration
- build-prod.ps1 : Script build production avec dart-define
- lib/core/constants/env_config.dart : Gestion environnements

### Documentation
- TODOS_IMPLEMENTED.md : Documentation complète TODOs

## Améliorations

### Architecture
- Refactoring injection de dépendances
- Amélioration routing et navigation
- Optimisation providers (UserProvider, FriendsProvider)

### UI/UX
- Amélioration thème et couleurs
- Optimisation animations
- Meilleure gestion erreurs

### Services
- Configuration API avec env_config
- Amélioration datasources (events, users)
- Optimisation modèles de données

test/domain/entities/user_test.dart

@@ -0,0 +1,150 @@
+import 'package:afterwork/domain/entities/user.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('User Entity', () {
+    const tUserId = '123';
+    const tUserLastName = 'Doe';
+    const tUserFirstName = 'John';
+    const tEmail = 'john.doe@example.com';
+    const tMotDePasse = 'hashedPassword123';
+    const tProfileImageUrl = 'https://example.com/profile.jpg';
+    const tEventsCount = 5;
+    const tFriendsCount = 10;
+    const tPostsCount = 15;
+    const tVisitedPlacesCount = 20;
+
+    test('should create a User instance with all required fields', () {
+      // Act
+      const user = User(
+        userId: tUserId,
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+      );
+
+      // Assert
+      expect(user.userId, tUserId);
+      expect(user.userLastName, tUserLastName);
+      expect(user.userFirstName, tUserFirstName);
+      expect(user.email, tEmail);
+      expect(user.motDePasse, tMotDePasse);
+      expect(user.profileImageUrl, tProfileImageUrl);
+      expect(user.eventsCount, 0); // Default value
+      expect(user.friendsCount, 0); // Default value
+      expect(user.postsCount, 0); // Default value
+      expect(user.visitedPlacesCount, 0); // Default value
+    });
+
+    test('should create a User instance with optional counts', () {
+      // Act
+      const user = User(
+        userId: tUserId,
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+        eventsCount: tEventsCount,
+        friendsCount: tFriendsCount,
+        postsCount: tPostsCount,
+        visitedPlacesCount: tVisitedPlacesCount,
+      );
+
+      // Assert
+      expect(user.eventsCount, tEventsCount);
+      expect(user.friendsCount, tFriendsCount);
+      expect(user.postsCount, tPostsCount);
+      expect(user.visitedPlacesCount, tVisitedPlacesCount);
+    });
+
+    test('should support value equality using Equatable', () {
+      // Arrange
+      const user1 = User(
+        userId: tUserId,
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+      );
+
+      const user2 = User(
+        userId: tUserId,
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+      );
+
+      // Assert
+      expect(user1, equals(user2));
+      expect(user1.hashCode, equals(user2.hashCode));
+    });
+
+    test('should not be equal when any field is different', () {
+      // Arrange
+      const user1 = User(
+        userId: tUserId,
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+      );
+
+      const user2 = User(
+        userId: 'different-id',
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+      );
+
+      // Assert
+      expect(user1, isNot(equals(user2)));
+    });
+
+    test('props should contain all fields for equality comparison', () {
+      // Arrange
+      const user = User(
+        userId: tUserId,
+        userLastName: tUserLastName,
+        userFirstName: tUserFirstName,
+        email: tEmail,
+        motDePasse: tMotDePasse,
+        profileImageUrl: tProfileImageUrl,
+        eventsCount: tEventsCount,
+        friendsCount: tFriendsCount,
+        postsCount: tPostsCount,
+        visitedPlacesCount: tVisitedPlacesCount,
+      );
+
+      // Act
+      final props = user.props;
+
+      // Assert
+      expect(props.length, 10);
+      expect(
+        props,
+        containsAll([
+          tUserId,
+          tUserLastName,
+          tUserFirstName,
+          tEmail,
+          tMotDePasse,
+          tProfileImageUrl,
+          tEventsCount,
+          tFriendsCount,
+          tPostsCount,
+          tVisitedPlacesCount,
+        ]),
+      );
+    });
+  });
+}
+