feat(server): add booking, payment, and scheduler modules

Booking: reservation with atomic transactions, cancellation with refund
logic based on cancelHoursLimit (23 tests)
Payment: WeChat Pay integration (mock), order lifecycle, membership
creation on payment callback (13 tests)
Scheduler: cron tasks for slot generation, cleanup, membership expiry (8 tests)
109 total tests passing across 9 test suites

packages/server/src/app.module.ts

@@ -7,6 +7,9 @@ import { AuthModule } from './auth/auth.module'
 import { StudioModule } from './studio/studio.module'
 import { TimeSlotModule } from './time-slot/time-slot.module'
 import { MembershipModule } from './membership/membership.module'
+import { BookingModule } from './booking/booking.module'
+import { SchedulerModule } from './scheduler/scheduler.module'
+import { PaymentModule } from './payment/payment.module'
 
 @Module({
   imports: [
@@ -20,6 +23,9 @@ import { MembershipModule } from './membership/membership.module'
     StudioModule,
     TimeSlotModule,
     MembershipModule,
+    BookingModule,
+    SchedulerModule,
+    PaymentModule,
   ],
   controllers: [AppController],
 })