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

lib/data/models/establishment_model.dart

@@ -0,0 +1,190 @@
+import '../../domain/entities/establishment.dart';
+
+/// Modèle de données pour les établissements (Data Transfer Object).
+class EstablishmentModel {
+  EstablishmentModel({
+    required this.id,
+    required this.name,
+    required this.type,
+    required this.address,
+    required this.city,
+    required this.postalCode,
+    this.description,
+    this.phoneNumber,
+    this.email,
+    this.website,
+    this.imageUrl,
+    this.rating,
+    this.priceRange,
+    this.capacity,
+    this.amenities = const [],
+    this.openingHours,
+    this.latitude,
+    this.longitude,
+  });
+
+  /// Factory pour créer un [EstablishmentModel] à partir d'un JSON.
+  factory EstablishmentModel.fromJson(Map<String, dynamic> json) {
+    return EstablishmentModel(
+      id: _parseId(json, 'id', ''),
+      name: _parseString(json, 'name', ''),
+      type: _parseType(json['type'] as String?),
+      address: _parseString(json, 'address', ''),
+      city: _parseString(json, 'city', ''),
+      postalCode: _parseString(json, 'postalCode', ''),
+      description: json['description'] as String?,
+      phoneNumber: json['phoneNumber'] as String?,
+      email: json['email'] as String?,
+      website: json['website'] as String?,
+      imageUrl: json['imageUrl'] as String?,
+      rating: json['rating'] != null ? (json['rating'] as num).toDouble() : null,
+      priceRange: _parsePriceRange(json['priceRange'] as String?),
+      capacity: json['capacity'] as int?,
+      amenities: json['amenities'] != null
+          ? List<String>.from(json['amenities'] as List)
+          : [],
+      openingHours: json['openingHours'] as String?,
+      latitude: json['latitude'] != null ? (json['latitude'] as num).toDouble() : null,
+      longitude: json['longitude'] != null ? (json['longitude'] as num).toDouble() : null,
+    );
+  }
+
+  final String id;
+  final String name;
+  final EstablishmentType type;
+  final String address;
+  final String city;
+  final String postalCode;
+  final String? description;
+  final String? phoneNumber;
+  final String? email;
+  final String? website;
+  final String? imageUrl;
+  final double? rating;
+  final PriceRange? priceRange;
+  final int? capacity;
+  final List<String> amenities;
+  final String? openingHours;
+  final double? latitude;
+  final double? longitude;
+
+  /// Convertit ce modèle en JSON pour l'envoi vers l'API.
+  Map<String, dynamic> toJson() {
+    return {
+      'id': id,
+      'name': name,
+      'type': _typeToString(type),
+      'address': address,
+      'city': city,
+      'postalCode': postalCode,
+      if (description != null) 'description': description,
+      if (phoneNumber != null) 'phoneNumber': phoneNumber,
+      if (email != null) 'email': email,
+      if (website != null) 'website': website,
+      if (imageUrl != null) 'imageUrl': imageUrl,
+      if (rating != null) 'rating': rating,
+      if (priceRange != null) 'priceRange': _priceRangeToString(priceRange!),
+      if (capacity != null) 'capacity': capacity,
+      if (amenities.isNotEmpty) 'amenities': amenities,
+      if (openingHours != null) 'openingHours': openingHours,
+      if (latitude != null) 'latitude': latitude,
+      if (longitude != null) 'longitude': longitude,
+    };
+  }
+
+  /// Convertit ce modèle vers une entité de domaine [Establishment].
+  Establishment toEntity() {
+    return Establishment(
+      id: id,
+      name: name,
+      type: type,
+      address: address,
+      city: city,
+      postalCode: postalCode,
+      description: description,
+      phoneNumber: phoneNumber,
+      email: email,
+      website: website,
+      imageUrl: imageUrl,
+      rating: rating,
+      priceRange: priceRange,
+      capacity: capacity,
+      amenities: amenities,
+      openingHours: openingHours,
+      latitude: latitude,
+      longitude: longitude,
+    );
+  }
+
+  // Méthodes de parsing
+  static String _parseString(Map<String, dynamic> json, String key, String defaultValue) {
+    return json[key] as String? ?? defaultValue;
+  }
+
+  static String _parseId(Map<String, dynamic> json, String key, String defaultValue) {
+    final value = json[key];
+    if (value == null) return defaultValue;
+    return value.toString();
+  }
+
+  static EstablishmentType _parseType(String? type) {
+    if (type == null) return EstablishmentType.other;
+
+    switch (type.toLowerCase()) {
+      case 'bar':
+        return EstablishmentType.bar;
+      case 'restaurant':
+        return EstablishmentType.restaurant;
+      case 'club':
+        return EstablishmentType.club;
+      case 'cafe':
+      case 'café':
+        return EstablishmentType.cafe;
+      case 'lounge':
+        return EstablishmentType.lounge;
+      case 'pub':
+        return EstablishmentType.pub;
+      case 'brewery':
+      case 'brasserie':
+        return EstablishmentType.brewery;
+      case 'winery':
+      case 'cave':
+        return EstablishmentType.winery;
+      default:
+        return EstablishmentType.other;
+    }
+  }
+
+  static PriceRange? _parsePriceRange(String? priceRange) {
+    if (priceRange == null) return null;
+
+    switch (priceRange.toLowerCase()) {
+      case 'cheap':
+      case 'économique':
+      case '€':
+        return PriceRange.cheap;
+      case 'moderate':
+      case 'modéré':
+      case '€€':
+        return PriceRange.moderate;
+      case 'expensive':
+      case 'cher':
+      case '€€€':
+        return PriceRange.expensive;
+      case 'luxury':
+      case 'luxe':
+      case '€€€€':
+        return PriceRange.luxury;
+      default:
+        return null;
+    }
+  }
+
+  static String _typeToString(EstablishmentType type) {
+    return type.toString().split('.').last;
+  }
+
+  static String _priceRangeToString(PriceRange priceRange) {
+    return priceRange.toString().split('.').last;
+  }
+}