feat: complete PRD verification fixes and deployment readiness

- 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

apps/server/src/rooms/rooms.module.ts

@@ -6,10 +6,10 @@ import { RoomExpense } from '../entities/room-expense.entity';
 import { RoomsService } from './rooms.service';
 import { RoomsController } from './rooms.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
-import { DepartmentsModule } from '../departments/departments.module';
+import { CommonModule } from '../common/common.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Room, Occupancy, RoomExpense]), OperationLogsModule, DepartmentsModule],
+  imports: [TypeOrmModule.forFeature([Room, Occupancy, RoomExpense]), OperationLogsModule, CommonModule],
   controllers: [RoomsController],
   providers: [RoomsService],
   exports: [RoomsService],