- Add CommonModule to provide/export CampusScope across business modules
- Replace DepartmentsModule imports with CommonModule in 11 modules
- Add missing Class/Tenant repository imports to StudentsModule and SchedulesModule
- Fix service specs with CampusScope, ClassRepository, StudentRepository mocks
- Move better-sqlite3 to optionalDependencies for production Docker builds
- Rewrite Dockerfiles for monorepo root build context
- Update docker-compose.yml service build contexts
- 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
