fix(admin): 迁移 antd v6 弃用 API 并清理控制台警告

- Card bordered -> variant；Modal maskClosable -> mask.closable
- InputNumber addonBefore/After -> prefix/suffix；Statistic valueStyle -> styles.content
- Alert message -> title；Steps items.description -> items.content
- 移除考勤页未挂载 Form 上的 setFieldsValue，消除 useForm 警告

apps/admin/src/pages/Attendance/AttendanceAdminWorkspace.tsx

@@ -134,7 +134,7 @@ export const AttendanceAdminWorkspace: React.FC<{
         </Spin>
       </section>
 
-      <Card className="student-record-card" bordered={false} title="原始考勤明细">
+      <Card className="student-record-card" variant="borderless" title="原始考勤明细">
         <Table<AttendanceRecordItem>
           rowKey="id"
           columns={columns}