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/bills/bills.module.ts

@@ -1,6 +1,6 @@
 import { Module } from '@nestjs/common';
 import { NotificationsModule } from '../notifications/notifications.module';
-import { DepartmentsModule } from '../departments/departments.module';
+import { CommonModule } from '../common/common.module';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { Bill } from '../entities/bill.entity';
 import { BillItem } from '../entities/bill-item.entity';
@@ -27,7 +27,7 @@ import { BillsController } from './bills.controller';
       Student,
     ]),
     NotificationsModule,
-    DepartmentsModule,
+    CommonModule,
   ],
   controllers: [BillsController],
   providers: [BillsService, BillsExportService],

apps/server/src/bills/bills.service.spec.ts

@@ -9,6 +9,7 @@ import { PersonalExpense } from '../entities/personal-expense.entity';
 import { Occupancy } from '../entities/occupancy.entity';
 import { Room } from '../entities/room.entity';
 import { Deposit } from '../entities/deposit.entity';
+import { CampusScope } from '../common/campus-scope';
 
 type MockRepository<T> = Partial<Record<keyof Repository<T>, jest.Mock>>;
 
@@ -56,7 +57,7 @@ describe('BillsService — generateBills', () => {
     occRepo = mockRepo<Occupancy>();
     roomRepo = mockRepo<Room>();
     depositRepo = mockRepo<Deposit>();
-    dataSource = { transaction: jest.fn() };
+    dataSource = { transaction: jest.fn(), query: jest.fn().mockResolvedValue([]) };
 
     const module: TestingModule = await Test.createTestingModule({
       providers: [
@@ -69,6 +70,7 @@ describe('BillsService — generateBills', () => {
         { provide: getRepositoryToken(Room), useValue: roomRepo },
         { provide: getRepositoryToken(Deposit), useValue: depositRepo },
         { provide: DataSource, useValue: dataSource },
+        { provide: CampusScope, useValue: { getScopeDepartmentIds: jest.fn().mockResolvedValue(null), filter: jest.fn((w: any) => w) } },
       ],
     }).compile();