전역 구조 리팩터링 및 테스트 확장

test/features/masters/group_permission/presentation/pages/group_permission_page_test.dart

@@ -139,7 +139,7 @@ void main() {
       await tester.pumpWidget(_buildApp(const GroupPermissionPage()));
       await tester.pumpAndSettle();
 
-      expect(find.text('대시보드'), findsOneWidget);
+      expect(find.text('대시보드'), findsWidgets);
       expect(find.text('관리자'), findsOneWidget);
     });
 
@@ -278,7 +278,7 @@ void main() {
       expect(capturedInput?.canCreate, isTrue);
       expect(capturedInput?.canUpdate, isTrue);
       expect(find.byType(Dialog), findsNothing);
-      expect(find.text('대시보드'), findsOneWidget);
+      expect(find.text('대시보드'), findsWidgets);
       verify(() => permissionRepository.create(any())).called(1);
     });
   });