refactor(server): remove Department/UserDepartment entities, CampusScope, and departmentId from all entities

- Delete department.entity.ts, user-department.entity.ts
- Remove Department/UserDepartment from entities/index.ts
- Remove departmentId column from 18 entities (AttendanceRecord, ArchiveAttachment, Bill, ClassSchedule, Classroom, ClassroomRental, Deposit, DepositInstallment, ExamScore, LearningRecord, Occupancy, PersonalExpense, ResultArchive, Room, RoomExpense, Student, StudentEnrollment, StudentProfile, StudentReport)
- Remove departments/ module entirely
- Delete campus-scope.ts, campus-scope.middleware.ts (request-utils.ts kept — it's just IP extraction)
- Simplify common.module.ts to empty module
- Remove CampusScopeMiddleware from app.module.ts
- Remove all CampusScope injections and filter calls across all services
- Remove departmentId from all DTOs and controllers
- Simplify dingtalk/wecom sync to only sync users (no dept table)
- Update seed module to remove department seeding
- Clean frontend compilation

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

@@ -9,7 +9,6 @@ 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>>;
 
@@ -70,7 +69,6 @@ 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();