fix(admin): UX improvements — silent fetch failures, empty states, batch loading guards, dashboard refresh

- Replace console.error-only catches with message.error user-facing notifications
  across Bills, Classes, ClassroomRentals, ClassroomSchedule, Classrooms, Deposits,
  Expenses, OperationLogs, Permissions, Roles, RoomVisual, Rooms, Students,
  Tenants, Users
- Add Empty component via Table locale prop on list pages: Bills, Classes,
  ClassroomRentals, Classrooms, Deposits, Expenses (room+personal), Occupancies,
  Rooms, Students, Tenants, Roles
- Add batchLoading state to batch delete/update operations: Bills (batchDelete,
  batchUpdateStatus), Expenses (batchDeleteRoom, batchDeletePersonal),
  Occupancies (batchCheckOut, batchDelete), Rooms (batchDelete),
  Students (batchDelete)
- Add refreshLoading indicator to Dashboard header when re-fetching data
- Consistent error pattern: catch (e: unknown) { const err = e as { message?: string }; message.error(...); }

apps/admin/src/pages/Roles/index.tsx

@@ -10,6 +10,7 @@ import {
   message,
   Card,
   Checkbox,
+  Empty,
 } from 'antd';
 import { PlusOutlined, EditOutlined, DeleteOutlined } from '@ant-design/icons';
 import api from '../../api';
@@ -52,8 +53,9 @@ const RolesPage: React.FC = () => {
       ]);
       setData(roles);
       setAllPerms(permTree);
-    } catch (e) {
-      console.error(e);
+    } catch (e: unknown) {
+      const err = e as { message?: string };
+      message.error(err?.message || '加载失败，请稍后重试');
     }
     setLoading(false);
   }, []);
@@ -224,10 +226,10 @@ const RolesPage: React.FC = () => {
         </PermissionButton>
       </div>
       <Table
-        columns={columns}
         dataSource={data}
         rowKey="id"
         loading={loading}
+        locale={{ emptyText: <Empty description="暂无数据" /> }}
         scroll={{ x: 900 }}
         pagination={false}
       />