- GET /classes/:id/roster/export — Excel export with 姓名/学号/加入日期/状态
- GET /attendance-records/export — Excel export with 姓名/班级/日期/时段/状态/来源/备注/打卡时间
- Add findAllForExport to AttendanceService (no pagination)
- Both use ExcelJS following classrooms controller downloadTemplate pattern