feat(server): add membership and time-slot modules

Membership: card type CRUD, deduction/restore logic, valid card lookup (15 tests)
TimeSlot: slot generation from week templates, availability query with booking
status, admin management, cleanup tasks (26 tests)
65 total tests passing

packages/server/src/app.module.ts

@@ -5,6 +5,8 @@ import { PrismaModule } from './prisma/prisma.module'
 import { UserModule } from './user/user.module'
 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'
 
 @Module({
   imports: [
@@ -16,6 +18,8 @@ import { StudioModule } from './studio/studio.module'
     AuthModule,
     UserModule,
     StudioModule,
+    TimeSlotModule,
+    MembershipModule,
   ],
   controllers: [AppController],
 })