feat(classes): add schedule and attendance-summary endpoints + frontend tabs

- Add GET /classes/:id/schedule returning ClassSchedule list with classroom name
- Add GET /classes/:id/attendance-summary returning attendance/absence/late rates
- Add 课表 and 出勤汇总 tabs to Classes detail page
- Register ClassSchedule and AttendanceRecord in ClassesModule

apps/server/src/classes/classes.module.ts

@@ -1,14 +1,14 @@
 import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { CommonModule } from '../common/common.module';
-import { Class, ClassStudent, ClassTeacher } from '../entities';
+import { Class, ClassStudent, ClassTeacher, ClassSchedule, AttendanceRecord } from '../entities';
 import { ClassesService } from './classes.service';
 import { ClassesController } from './classes.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
 import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher]), OperationLogsModule, NotificationsModule, CommonModule],
+  imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher, ClassSchedule, AttendanceRecord]), OperationLogsModule, NotificationsModule, CommonModule],
   controllers: [ClassesController],
   providers: [ClassesService],
   exports: [ClassesService],