feat: add class roster export button in class detail page

apps/admin/src/pages/Classes/detail.tsx

@@ -5,7 +5,7 @@ import {
   Popconfirm, message, Form, Input, DatePicker, InputNumber,
 } from 'antd';
 import type { ColumnsType } from 'antd/es/table';
-import { ArrowLeftOutlined, PlusOutlined } from '@ant-design/icons';
+import { ArrowLeftOutlined, PlusOutlined, DownloadOutlined } from '@ant-design/icons';
 import dayjs from 'dayjs';
 import api from '../../api';
 import PermissionButton from '../../components/PermissionButton';
@@ -402,10 +402,36 @@ const ClassDetailPage: React.FC = () => {
                   icon={<PlusOutlined />}
                   type="primary"
                   onClick={openStudentModal}
-                  style={{ marginBottom: 16 }}
+                  style={{ marginBottom: 16, marginRight: 8 }}
                 >
                   添加学员
                 </Button>
+                <PermissionButton
+                  permission="class:view"
+                  icon={<DownloadOutlined />}
+                  onClick={() => {
+                    const token = localStorage.getItem('token');
+                    fetch(`/api/classes/${id}/roster/export`, {
+                      headers: { Authorization: `Bearer ${token}` },
+                    })
+                      .then((res) => {
+                        if (!res.ok) throw new Error('导出失败');
+                        return res.blob();
+                      })
+                      .then((blob) => {
+                        const url = URL.createObjectURL(blob);
+                        const a = document.createElement('a');
+                        a.href = url;
+                        a.download = `班级花名册-${detail?.name || id}.xlsx`;
+                        a.click();
+                        URL.revokeObjectURL(url);
+                        message.success('花名册导出成功');
+                      })
+                      .catch(() => message.error('花名册导出失败'));
+                  }}
+                >
+                  导出花名册
+                </PermissionButton>
                 <Table<ClassStudent>
                   columns={studentColumns}
                   dataSource={students}