feat(task1): restructure directories for turborepo monorepo

- Move backend/ to apps/server/ via git mv
- Move frontend/ to apps/admin/ via git mv
- Create packages/typescript-config/ with base, nestjs, and react-vite presets

apps/server/src/bills/bills.module.ts

@@ -0,0 +1,20 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { Bill } from '../entities/bill.entity';
+import { BillItem } from '../entities/bill-item.entity';
+import { RoomExpense } from '../entities/room-expense.entity';
+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 { BillsService } from './bills.service';
+import { BillsExportService } from './bills-export.service';
+import { BillsController } from './bills.controller';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([Bill, BillItem, RoomExpense, PersonalExpense, Occupancy, Room, Deposit])],
+  controllers: [BillsController],
+  providers: [BillsService, BillsExportService],
+  exports: [BillsService],
+})
+export class BillsModule {}