修复bug,添加备案号悬挂功能

backend/middleware/permission.py

@@ -82,6 +82,15 @@ class PermissionChecker:
         role = await PermissionChecker.get_user_role(user_id)
         return role in ["班主任", "学习委员"]
     
+    @staticmethod
+    async def get_user_class_id(user_id: int) -> Optional[int]:
+        """
+        获取用户关联的班级ID
+        单班级系统，固定返回1
+        """
+        # 本系统为单班级设计，class_id 固定为 1
+        return 1
+    
     @staticmethod
     async def check_can_revoke(user_id: int, record_id: int) -> bool:
         """