fix(archive): 档案聚合接口 null 字段归一化为空串

避免可选列缺省返回 null 导致前端响应校验报「字段格式异常」

apps/server/src/archive/archive.service.spec.ts

@@ -36,4 +36,54 @@ describe('ArchiveService.getProfile', () => {
     expect(response).toMatchObject({ student, result, attendances: [] });
     expect(response).not.toHaveProperty('resultArchive');
   });
+
+  it('将学生可空字符串字段归一化为空串，避免前端校验报格式异常', async () => {
+    const student = {
+      id: 7,
+      name: '测试学生',
+      phone: null,
+      idNumber: null,
+      studentNo: null,
+      gender: null,
+      ethnicity: null,
+      emergencyContact: null,
+      emergencyPhone: null,
+      supervisor: null,
+    };
+    const emptyRepos = {
+      profile: { findOne: jest.fn().mockResolvedValue(null) },
+      enrollment: { find: jest.fn().mockResolvedValue([]) },
+      exam: { find: jest.fn().mockResolvedValue([]) },
+      learning: { find: jest.fn().mockResolvedValue([]) },
+      result: { findOne: jest.fn().mockResolvedValue(null) },
+      attachment: { find: jest.fn().mockResolvedValue([]) },
+      attendance: { find: jest.fn().mockResolvedValue([]) },
+    };
+    const service = new ArchiveService(
+      { findOne: jest.fn().mockResolvedValue(student) } as never,
+      emptyRepos.profile as never,
+      emptyRepos.enrollment as never,
+      emptyRepos.exam as never,
+      emptyRepos.learning as never,
+      emptyRepos.result as never,
+      emptyRepos.attachment as never,
+      emptyRepos.attendance as never,
+      {} as never,
+    );
+
+    const response = await service.getProfile(7);
+
+    expect(response.student).toMatchObject({
+      id: 7,
+      name: '测试学生',
+      phone: '',
+      idNumber: '',
+      studentNo: '',
+      gender: '',
+      ethnicity: '',
+      emergencyContact: '',
+      emergencyPhone: '',
+      supervisor: '',
+    });
+  });
 });