feat(menu-permissions): 메뉴 API 연동으로 사이드바 권한 정비

- .env.development.example과 lib/core/config/environment.dart, lib/core/permissions/permission_manager.dart에서 PERMISSION__ 폴백을 view 전용으로 좁히고 기본 정책을 명시적으로 거부하도록 재정비했다

- lib/core/navigation/*, lib/core/routing/app_router.dart, lib/widgets/app_shell.dart, lib/main.dart에서 메뉴 매니페스트·카탈로그를 도입해 /menus 응답을 캐싱하고 라우터·사이드바·Breadcrumb가 동일 menu_code/route_path를 쓰도록 리팩터링했다

- lib/core/permissions/permission_resources.dart와 그룹 권한/메뉴 마스터 모듈을 menu_code 기반 CRUD 및 Catalog 경로 정합성 검사로 전환하고 PermissionSynchronizer·PermissionBootstrapper를 확장했다

- test/helpers/test_permissions.dart, test/widgets/app_shell_test.dart 등 신규 구조를 반영하는 테스트·골든과 doc/frontend_menu_permission_tasks.md 문서를 보강했다

lib/features/masters/group_permission/presentation/dialogs/group_permission_detail_dialog.dart

@@ -366,7 +366,7 @@ class _GroupPermissionForm extends StatefulWidget {
 
 class _GroupPermissionFormState extends State<_GroupPermissionForm> {
   int? _selectedGroup;
-  int? _selectedMenu;
+  String? _selectedMenu;
   late bool _canCreate;
   late bool _canRead;
   late bool _canUpdate;
@@ -385,7 +385,7 @@ class _GroupPermissionFormState extends State<_GroupPermissionForm> {
     super.initState();
     final permission = widget.permission;
     _selectedGroup = permission?.group.id;
-    _selectedMenu = permission?.menu.id;
+    _selectedMenu = permission?.menu.menuCode;
     _canCreate = permission?.canCreate ?? false;
     _canRead = permission?.canRead ?? true;
     _canUpdate = permission?.canUpdate ?? false;
@@ -457,7 +457,7 @@ class _GroupPermissionFormState extends State<_GroupPermissionForm> {
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             children: [
-              ShadSelect<int>(
+              ShadSelect<String>(
                 initialValue: _selectedMenu,
                 placeholder: Text(
                   widget.isLoadingMenus ? '메뉴 로딩중...' : '메뉴 선택',
@@ -475,9 +475,10 @@ class _GroupPermissionFormState extends State<_GroupPermissionForm> {
                         });
                       },
                 options: widget.menus
+                    .where((menu) => menu.menuCode.isNotEmpty)
                     .map(
-                      (menu) => ShadOption<int>(
-                        value: menu.id!,
+                      (menu) => ShadOption<String>(
+                        value: menu.menuCode,
                         child: Text(menu.menuName),
                       ),
                     )
@@ -612,7 +613,7 @@ class _GroupPermissionFormState extends State<_GroupPermissionForm> {
     final note = _noteController.text.trim();
     final input = GroupPermissionInput(
       groupId: _selectedGroup!,
-      menuId: _selectedMenu!,
+      menuCode: _selectedMenu!,
       canCreate: _canCreate,
       canRead: _canRead,
       canUpdate: _canUpdate,
@@ -648,13 +649,13 @@ class _GroupPermissionFormState extends State<_GroupPermissionForm> {
     return group.groupName;
   }
 
-  String _resolveMenuLabel(int? id) {
-    if (id == null) {
+  String _resolveMenuLabel(String? code) {
+    if (code == null) {
       return widget.isLoadingMenus ? '메뉴 로딩중...' : '메뉴 선택';
     }
     final menu = widget.menus.firstWhere(
-      (item) => item.id == id,
-      orElse: () => MenuItem(id: id, menuCode: '', menuName: '알 수 없음'),
+      (item) => item.menuCode == code,
+      orElse: () => MenuItem(menuCode: code, menuName: '알 수 없음'),
     );
     return menu.menuName;
   }