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/classes/classes.module.ts

@@ -1,6 +1,6 @@
 import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
-import { DepartmentsModule } from '../departments/departments.module';
+import { CommonModule } from '../common/common.module';
 import { Class, ClassStudent, ClassTeacher } from '../entities';
 import { ClassesService } from './classes.service';
 import { ClassesController } from './classes.controller';
@@ -8,7 +8,7 @@ import { OperationLogsModule } from '../operation-logs/operation-logs.module';
 import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher]), OperationLogsModule, NotificationsModule, DepartmentsModule],
+  imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher]), OperationLogsModule, NotificationsModule, CommonModule],
   controllers: [ClassesController],
   providers: [ClassesService],
   exports: [ClassesService],