fix(imports): 修复 AI 导入向导多工作表与表头误判

- AI resolve 生成向导时按阶段携带全部 sheetNames，不再只取第一张表
- ImportStageRequest 支持 sheets 数组并兼容旧 sheet；手动重传同步修复
- headerMatches 收窄为单向包含，避免宿舍号被原/新宿舍号反向匹配
- suggestStep 增加入住/换宿显式表头信号，修复入住表误判为换宿
- 预检与预览按工作表逐表解析列映射，兼容异构表头
- 修复预检卡生成向导成功后按钮未复位 loading 的问题
- 补充 mapping/预检/run/ai-chat 多工作表测试

apps/server/src/ai-chat/ai-chat.service.spec.ts

@@ -1884,7 +1884,7 @@ describe('AiChatService', () => {
       'ai',
       expect.objectContaining({ originalName: 'students.xlsx' }),
       3,
-      [{ stepKey: 'students', sheet: '学生', headerRow: 1 }],
+      [{ stepKey: 'students', sheets: ['学生'], headerRow: 1 }],
       { students: { name: '姓名', studentNo: '学号' } },
       { updateExisting: false },
     );
@@ -1906,6 +1906,101 @@ describe('AiChatService', () => {
     ).toMatchObject({ resolved: true, runId: 'run-9' });
   });
 
+  it('resolveImportPreflight 多工作表阶段携带全部 sheetNames 生成导入任务', async () => {
+    const { service } = createService();
+    const conversations = {
+      findOne: jest.fn().mockResolvedValue({ id: 3, userId: 7 }),
+    };
+    const message = {
+      id: 42,
+      conversationId: 3,
+      role: 'assistant',
+      metadata: {
+        a2uiImportPreflight: {
+          verdict: 'needs_input',
+          stages: [
+            {
+              stepKey: 'checkins',
+              label: '入住管理',
+              sheetNames: ['四人间女', '四人间男'],
+              headers: ['姓名', '学号', '手机号', '宿舍号', '入住日期'],
+              mapping: { name: '姓名', roomNumber: '宿舍号' },
+              missingRequired: [],
+              total: 2,
+              create: 2,
+              update: 0,
+              error: 0,
+              skip: 0,
+            },
+          ],
+          blocks: [],
+          questions: [],
+          nextSteps: [],
+          errorSamples: [],
+          attachmentId: 9,
+          headerRow: 1,
+          permittedSteps: ['checkins'],
+          resolved: false,
+          runId: null,
+        },
+      },
+    };
+    const messages = {
+      findOne: jest.fn().mockResolvedValue(message),
+      save: jest.fn(async (value) => value),
+      exists: jest.fn().mockResolvedValue(false),
+    };
+    const attachmentService = {
+      requireReadyOwned: jest.fn().mockResolvedValue([
+        {
+          id: 9,
+          mimeType: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+          originalName: 'dorm.xlsx',
+          size: 10,
+        },
+      ]),
+      readStoredBuffer: jest.fn().mockResolvedValue(Buffer.from('x')),
+    };
+    const importsService = {
+      createRun: jest.fn().mockResolvedValue({
+        id: 'run-9',
+        fileName: 'dorm.xlsx',
+        sheets: [],
+        steps: [
+          {
+            stepKey: 'checkins',
+            label: '入住管理',
+            sheets: ['四人间女', '四人间男'],
+            status: 'pending',
+          },
+        ],
+      }),
+    };
+    (service as unknown as { conversations: unknown }).conversations = conversations;
+    (service as unknown as { messages: unknown }).messages = messages;
+    (service as unknown as { attachmentService: unknown }).attachmentService = attachmentService;
+    (service as unknown as { importsService: unknown }).importsService = importsService;
+
+    await service.resolveImportPreflight(
+      authenticatedUser,
+      42,
+      { clientRequestId: 'multi-sheet', mapping: {}, settings: {} },
+      new AbortController().signal,
+      jest.fn(),
+      jest.fn(),
+    );
+
+    expect(importsService.createRun).toHaveBeenCalledWith(
+      { id: 7, permissions: ['ai:chat:use'], isSuperAdmin: false },
+      'ai',
+      expect.objectContaining({ originalName: 'dorm.xlsx' }),
+      3,
+      [{ stepKey: 'checkins', sheets: ['四人间女', '四人间男'], headerRow: 1 }],
+      {},
+      {},
+    );
+  });
+
   it('resolveImportPreflight 已生成向导时幂等重放，不重复建任务', async () => {
     const { service } = createService();
     const conversations = {