chore: remove student application feature from frontend

- Remove student application section (提示和按钮) from personal settings page
- Remove student status column (学员状态) from user management table
- Remove set_student action (设为学员) from user operations dropdown
- Remove unused renderStudentStatus, handleApplyStudent, studentApplying state

web/src/components/settings/PersonalSetting.jsx

@@ -84,7 +84,6 @@ const PersonalSetting = () => {
   const [passkeyRegisterLoading, setPasskeyRegisterLoading] = useState(false);
   const [passkeyDeleteLoading, setPasskeyDeleteLoading] = useState(false);
   const [passkeySupported, setPasskeySupported] = useState(false);
-  const [studentApplying, setStudentApplying] = useState(false);
   const [notificationSettings, setNotificationSettings] = useState({
     warningType: 'email',
     warningThreshold: 100000,
@@ -554,24 +553,6 @@ const PersonalSetting = () => {
     }
   };
 
-  const handleApplyStudent = async () => {
-    setStudentApplying(true);
-    try {
-      const res = await API.post('/api/user/student/apply');
-      const { success, message } = res.data;
-      if (success) {
-        showSuccess(message || t('学员申请已提交'));
-        await getUserData();
-      } else {
-        showError(message || t('提交申请失败'));
-      }
-    } catch (error) {
-      showError(t('提交申请失败'));
-    } finally {
-      setStudentApplying(false);
-    }
-  };
-
   return (
     <div className='mt-[60px]'>
       <div className='flex justify-center'>
@@ -582,32 +563,6 @@ const PersonalSetting = () => {
             <Card>
               <div className='flex flex-col md:flex-row md:items-center md:justify-between gap-3'>
                 <div>
-                  <Typography.Text strong>{t('学员身份申请')}</Typography.Text>
-                  <Typography.Text
-                    type='tertiary'
-                    size='small'
-                    className='block mt-1'
-                  >
-                    {userState?.user?.is_student
-                      ? t('当前已是学员身份')
-                      : userState?.user?.student_status === 1
-                        ? t('申请已提交，等待管理员审批')
-                        : t('提交申请后由管理员审批，审批通过将发放学员奖励')}
-                  </Typography.Text>
-                </div>
-                <Button
-                  type='primary'
-                  loading={studentApplying}
-                  disabled={
-                    userState?.user?.is_student ||
-                    userState?.user?.student_status === 1
-                  }
-                  onClick={handleApplyStudent}
-                >
-                  {t('申请学员身份')}
-                </Button>
-              </div>
-            </Card>
           </div>
 
           {/* 签到日历 - 仅在启用时显示 */}

web/src/components/table/users/UsersColumnDefs.jsx

@@ -270,35 +270,6 @@ const renderInviteInfo = (text, record, t) => {
   );
 };
 
-const renderStudentStatus = (record, t) => {
-  if (record.is_student === 1 || record.is_student === true) {
-    return (
-      <Tag color='green' shape='circle' className='!text-xs'>
-        {t('学员')}
-      </Tag>
-    );
-  }
-  if (record.student_status === 1) {
-    return (
-      <Tag color='orange' shape='circle' className='!text-xs'>
-        {t('待审批')}
-      </Tag>
-    );
-  }
-  if (record.student_status === 3) {
-    return (
-      <Tag color='grey' shape='circle' className='!text-xs'>
-        {t('已拒绝')}
-      </Tag>
-    );
-  }
-  return (
-    <Tag color='white' shape='circle' className='!text-xs'>
-      {t('非学员')}
-    </Tag>
-  );
-};
-
 /**
  * Render operations column
  */
@@ -400,21 +371,7 @@ const renderOperations = (
           },
         ]
       : []),
-    ...(record.role === USER_ROLES.USER &&
-    record.status === 1 &&
-    record.student_status !== 1 &&
-    !(record.is_student === 1 || record.is_student === true)
-      ? [
-          {
-            node: 'item',
-            name: t('设为学员'),
-            onClick: () => manageUser(record.id, 'set_student', record),
-          },
-          {
-            node: 'divider',
-          },
-        ]
-      : []),
+
     {
       node: 'item',
       name: t('注销'),
@@ -562,11 +519,7 @@ export const getUsersColumns = ({
         return <div>{renderRole(text, record, t)}</div>;
       },
     },
-    {
-      title: t('学员状态'),
-      dataIndex: 'student_status',
-      render: (text, record) => renderStudentStatus(record, t),
-    },
+
     {
       title: t('邀请信息'),
       dataIndex: 'invite',