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/schedules/schedules.service.spec.ts

@@ -4,6 +4,8 @@ import { ConflictException } from '@nestjs/common';
 import { Repository } from 'typeorm';
 import { SchedulesService } from './schedules.service';
 import { ClassSchedule } from '../entities/class-schedule.entity';
+import { Class } from '../entities/class.entity';
+import { CampusScope } from '../common/campus-scope';
 
 /** Build a mock query-builder where each chain method returns `this`. */
 function mockQueryBuilder<T>(results: T[] = []) {
@@ -28,6 +30,8 @@ describe('SchedulesService — checkConflict', () => {
       providers: [
         SchedulesService,
         { provide: getRepositoryToken(ClassSchedule), useValue: mockRepo },
+        { provide: getRepositoryToken(Class), useValue: { find: jest.fn().mockResolvedValue([]) } },
+        { provide: CampusScope, useValue: { getScopeDepartmentIds: jest.fn().mockResolvedValue(null), filter: jest.fn((w: any) => w) } },
       ],
     }).compile();