feat(core): refonte architecture transverse (cache, network, websocket, DI)

- lib/app : app.dart, router mis à jour (routes nouveaux modules)
- lib/core/cache : cache_service + cached_datasource_decorator
- lib/core/network : api_client, offline_manager, retry_policy
- lib/core/websocket : websocket service (reconnexion exponentielle, heartbeat)
- lib/core/di : injection + register_module
- lib/core/storage : pending_operations_store (offline support)
- lib/core/navigation : main_navigation_layout (onglets par rôle)
- lib/core/config : environment, lcb_ft_constants
- lib/core/utils : error_formatter, validators
- pubspec.yaml/lock : dépendances mises à jour

lib/core/navigation/main_navigation_layout.dart

@@ -118,7 +118,7 @@ class _MainNavigationLayoutState extends State<MainNavigationLayout> {
             statusBarIconBrightness: Brightness.dark,
           ),
           child: Scaffold(
-            backgroundColor: ColorTokens.background,
+            backgroundColor: Theme.of(context).scaffoldBackgroundColor,
             body: SafeArea(
               top: true,
               bottom: false,
@@ -199,12 +199,13 @@ class _PillNavigationBar extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final scheme = Theme.of(context).colorScheme;
     return Container(
       decoration: BoxDecoration(
-        color: ColorTokens.surface,
+        color: scheme.surface,
         boxShadow: [
           BoxShadow(
-            color: ColorTokens.shadow,
+            color: scheme.shadow.withOpacity(0.12),
             blurRadius: 12,
             offset: const Offset(0, -2),
           ),

lib/core/network/api_client.dart

@@ -1,6 +1,7 @@
 import 'package:dio/dio.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
+import '../../shared/design_system/tokens/app_colors.dart';
 import 'package:injectable/injectable.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 import '../../app/app.dart';
@@ -35,17 +36,7 @@ class ApiClient {
       ),
     );
 
-    // Intercepteur de Log (Uniquement en Dev)
-    if (AppConfig.enableLogging) {
-      _dio.interceptors.add(LogInterceptor(
-        requestHeader: true,
-        requestBody: true,
-        responseBody: true,
-        logPrint: (obj) => print('🌐 [API] $obj'),
-      ));
-    }
-
-    // Intercepteur de Token & Refresh automatique
+    // Intercepteur de Token & Refresh automatique (doit être AVANT le logger)
     _dio.interceptors.add(
       InterceptorsWrapper(
         onRequest: (options, handler) async {
@@ -112,6 +103,16 @@ class ApiClient {
         },
       ),
     );
+
+    // Intercepteur de Log (après le token pour voir le Bearer dans les logs)
+    if (AppConfig.enableLogging) {
+      _dio.interceptors.add(LogInterceptor(
+        requestHeader: true,
+        requestBody: true,
+        responseBody: true,
+        logPrint: (obj) => print('🌐 [API] $obj'),
+      ));
+    }
   }
 
   void _forceLogout() {
@@ -132,7 +133,7 @@ class ApiClient {
                 ),
               ],
             ),
-            backgroundColor: Colors.orange.shade700,
+            backgroundColor: AppColors.warning,
             duration: const Duration(seconds: 4),
             behavior: SnackBarBehavior.floating,
           ),

lib/core/websocket/websocket_service.dart

@@ -77,6 +77,17 @@ abstract class WebSocketEvent {
           organizationId: json['organizationId'] as String?,
         );
 
+      case 'NOUVEAU_MESSAGE':
+      case 'MESSAGE_SUPPRIME':
+      case 'CONVERSATION_LUE':
+        return ChatMessageEvent(
+          eventType: eventType,
+          timestamp: timestamp,
+          data: data,
+          conversationId: json['conversationId'] as String?,
+          organizationId: json['organizationId'] as String?,
+        );
+
       default:
         return GenericEvent(
           eventType: eventType,
@@ -144,6 +155,19 @@ class ContributionEvent extends WebSocketEvent {
   });
 }
 
+class ChatMessageEvent extends WebSocketEvent {
+  final String? conversationId;
+  final String? organizationId;
+
+  ChatMessageEvent({
+    required super.eventType,
+    required super.timestamp,
+    required super.data,
+    this.conversationId,
+    this.organizationId,
+  });
+}
+
 class GenericEvent extends WebSocketEvent {
   GenericEvent({
     required super.eventType,