feat: improve attendance scheduling and API validation

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

@@ -39,6 +39,7 @@ interface ClassScheduleItem {
   weekDay: number;
   startTime: string;
   endTime: string;
+  attendanceAdvanceMinutes: number;
   startDate: string;
   endDate: string;
   subject: string;
@@ -353,6 +354,7 @@ const ClassDetailPage: React.FC = () => {
     { title: '教室', dataIndex: 'classroomName', render: (v: string | null) => v || '-' },
     { title: '星期', dataIndex: 'weekDay', render: (v: number) => WEEK_DAY_MAP[v] || v },
     { title: '时间', render: (_: unknown, r: ClassScheduleItem) => `${r.startTime} - ${r.endTime}` },
+    { title: '签到窗口', render: (_: unknown, r: ClassScheduleItem) => `课前 ${r.attendanceAdvanceMinutes ?? 30} 分钟至下课` },
     { title: '日期范围', render: (_: unknown, r: ClassScheduleItem) => `${r.startDate} ~ ${r.endDate}` },
     { title: '科目', dataIndex: 'subject' },
     { title: '类型', dataIndex: 'scheduleType', render: (v: string) => SCHEDULE_TYPE_MAP[v] || v },