feat(admin): 用户体验体系化提升与高危缺陷修复

UX 缺陷修复:
- 校验失败不再卡死弹窗按钮(Users/Roles/Bills)
- 押金收取/批量收取/添加分期防重复提交;切换房型重置勾选
- AI 表单/批量确认不再出现"假成功"
- Dashboard 各数据模块独立加载,单接口失败不再整页清零
- 房间可视化加载失败显示错误态而非永久转圈
- 学生编辑表单回填前重置,避免字段残留污染
- 覆盖式导入增加二次确认;恢复默认考勤时段确认并同步表单
- 金数据匹配关闭前确认,同步中禁止误关

体验提升:
- 新增统一 QueryErrorState/QueryEmpty,20+ 页面加载失败显示错误态与重试
- 全局 ErrorBoundary + RouteKeeper 逐页兜底
- 新增 usePageVisible/useVisibleRefetch,保活页面切回自动刷新数据
- 新增首次登录角色引导 RoleTour 与业务闭环 NextStepHint 引导卡
- 重构 A2UI:useSubmissionState/useXCardSurface 收敛状态与命令生命周期,
  ArtifactErrorBoundary 渲染降级,图表空数据占位
- AI 助手欢迎语与建议话术按角色定制,会话列表空态引导
- 更新 a2ui-contract.md 契约文档说明实现现状

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

@@ -39,6 +39,8 @@ import { useApiMutation } from '../../hooks/useApiMutation';
 import { validateResponse } from '../../utils/validate';
 import { classOptionsSchema, examsSchema } from '../../api/schemas';
 import { getErrorMessage } from '../../utils/error';
+import { QueryErrorState } from '../../components/QueryState';
+import { useVisibleRefetch } from '../../hooks/usePageVisible';
 
 const ExamsPage: React.FC = () => {
   const { modal } = App.useApp();
@@ -76,7 +78,7 @@ const ExamsPage: React.FC = () => {
     },
   });
 
-  const { data = [], isFetching } = useQuery<ExamItem[]>({
+  const { data = [], isFetching, isError, refetch } = useQuery<ExamItem[]>({
     queryKey: [
       'exams',
       debouncedFilters.keyword,
@@ -85,26 +87,23 @@ const ExamsPage: React.FC = () => {
       debouncedFilters.showArchived,
     ],
     queryFn: async () => {
-      try {
-        const params = new URLSearchParams();
-        if (debouncedFilters.keyword.trim())
-          params.set('keyword', debouncedFilters.keyword.trim());
-        if (debouncedFilters.examType) params.set('examType', debouncedFilters.examType);
-        if (debouncedFilters.classId) params.set('classId', String(debouncedFilters.classId));
-        params.set('isArchived', String(debouncedFilters.showArchived));
-        return (
-          validateResponse<ExamItem[]>(
-            examsSchema,
-            await api.get<ExamItem[]>(`/exams?${params.toString()}`),
-          ) ?? []
-        );
-      } catch (error) {
-        message.error(getErrorMessage(error, '加载考试失败'));
-        return [];
-      }
+      const params = new URLSearchParams();
+      if (debouncedFilters.keyword.trim())
+        params.set('keyword', debouncedFilters.keyword.trim());
+      if (debouncedFilters.examType) params.set('examType', debouncedFilters.examType);
+      if (debouncedFilters.classId) params.set('classId', String(debouncedFilters.classId));
+      params.set('isArchived', String(debouncedFilters.showArchived));
+      return (
+        validateResponse<ExamItem[]>(
+          examsSchema,
+          await api.get<ExamItem[]>(`/exams?${params.toString()}`),
+        ) ?? []
+      );
     },
   });
   const loading = isFetching;
+  // RouteKeeper 保活页面切回时刷新考试列表
+  useVisibleRefetch(['exams']);
 
   const saveMutation = useApiMutation(
     async (payload: Record<string, unknown>) => api.post('/exams', payload),
@@ -343,7 +342,13 @@ const ExamsPage: React.FC = () => {
         </Space>
       </div>
 
-      {data.length === 0 && !loading ? (
+      {isError ? (
+        <QueryErrorState
+          title="考试数据加载失败"
+          description="请检查网络后重试。"
+          onRetry={() => void refetch()}
+        />
+      ) : data.length === 0 && !loading ? (
         <div className="exam-empty">
           <Empty description="暂无考试" />
         </div>