feat(mobile): Implement Keycloak WebView authentication with HTTP callback

- Replace flutter_appauth with custom WebView implementation to resolve deep link issues
- Add KeycloakWebViewAuthService with integrated WebView for seamless authentication
- Configure Android manifest for HTTP cleartext traffic support
- Add network security config for development environment (192.168.1.11)
- Update Keycloak client to use HTTP callback endpoint (http://192.168.1.11:8080/auth/callback)
- Remove obsolete keycloak_auth_service.dart and temporary scripts
- Clean up dependencies and regenerate injection configuration
- Tested successfully on multiple Android devices (Xiaomi 2201116TG, SM A725F)

BREAKING CHANGE: Authentication flow now uses WebView instead of external browser
- Users will see Keycloak login page within the app instead of browser redirect
- Resolves ERR_CLEARTEXT_NOT_PERMITTED and deep link state management issues
- Maintains full OIDC compliance with PKCE flow and secure token storage

Technical improvements:
- WebView with custom navigation delegate for callback handling
- Automatic token extraction and user info parsing from JWT
- Proper error handling and user feedback
- Consistent authentication state management across app lifecycle

unionflow-mobile-apps/lib/features/members/presentation/pages/membre_edit_page.dart

@@ -7,6 +7,8 @@ import '../../../../core/models/membre_model.dart';
 import '../../../../shared/theme/app_theme.dart';
 import '../../../../shared/widgets/custom_text_field.dart';
 import '../../../../shared/widgets/buttons/buttons.dart';
+import '../../../../core/auth/services/permission_service.dart';
+import '../../../../shared/widgets/permission_widget.dart';
 import '../bloc/membres_bloc.dart';
 import '../bloc/membres_event.dart';
 import '../bloc/membres_state.dart';
@@ -25,7 +27,7 @@ class MembreEditPage extends StatefulWidget {
 }
 
 class _MembreEditPageState extends State<MembreEditPage>
-    with SingleTickerProviderStateMixin {
+    with SingleTickerProviderStateMixin, PermissionMixin {
   late MembresBloc _membresBloc;
   late TabController _tabController;
   final _formKey = GlobalKey<FormState>();
@@ -53,12 +55,22 @@ class _MembreEditPageState extends State<MembreEditPage>
   @override
   void initState() {
     super.initState();
+
+    // Vérification des permissions d'accès
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!permissionService.canEditMembers) {
+        showPermissionError(context, 'Vous n\'avez pas les permissions pour modifier les membres');
+        Navigator.of(context).pop();
+        return;
+      }
+    });
+
     _membresBloc = getIt<MembresBloc>();
     _tabController = TabController(length: 3, vsync: this);
-    
+
     // Pré-remplir les champs avec les données existantes
     _populateFields();
-    
+
     // Écouter les changements pour détecter les modifications
     _setupChangeListeners();
   }
@@ -184,10 +196,12 @@ class _MembreEditPageState extends State<MembreEditPage>
       ),
       actions: [
         if (_hasChanges)
-          IconButton(
+          PermissionIconButton(
+            permission: () => permissionService.canEditMembers,
             icon: const Icon(Icons.save),
             onPressed: _submitForm,
             tooltip: 'Sauvegarder',
+            disabledMessage: 'Vous n\'avez pas les permissions pour modifier ce membre',
           ),
         IconButton(
           icon: const Icon(Icons.help_outline),
@@ -939,6 +953,12 @@ class _MembreEditPageState extends State<MembreEditPage>
   }
 
   void _submitForm() {
+    // Vérification des permissions
+    if (!permissionService.canEditMembers) {
+      showPermissionError(context, 'Vous n\'avez pas les permissions pour modifier ce membre');
+      return;
+    }
+
     if (!_formKey.currentState!.validate()) {
       return;
     }
@@ -948,6 +968,12 @@ class _MembreEditPageState extends State<MembreEditPage>
       return;
     }
 
+    // Log de l'action pour audit
+    permissionService.logAction('Modification membre', details: {
+      'membreId': widget.membre.id,
+      'nom': '${widget.membre.prenom} ${widget.membre.nom}',
+    });
+
     setState(() {
       _isLoading = true;
     });