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/students/students.module.ts

@@ -1,14 +1,16 @@
 import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { Student } from '../entities/student.entity';
-import { DepartmentsModule } from '../departments/departments.module';
+import { Class } from '../entities/class.entity';
+import { Tenant } from '../entities/tenant.entity';
+import { CommonModule } from '../common/common.module';
 import { ClassStudent } from '../entities/class-student.entity';
 import { AttendanceRecord } from '../entities/attendance-record.entity';
 import { StudentsService } from './students.service';
 import { StudentsController } from './students.controller';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Student, ClassStudent, AttendanceRecord]), DepartmentsModule],
+  imports: [TypeOrmModule.forFeature([Student, Class, ClassStudent, AttendanceRecord, Tenant]), CommonModule],
   controllers: [StudentsController],
   providers: [StudentsService],
   exports: [StudentsService],