feat: Full petmaster CRM with NestJS API and React frontend

- Client management (CRUD with JSONB custom fields)
- Pet profiles
- Service catalog with per-client pricing
- Booking calendar with recurring appointments
- Invoicing with Stripe integration
- Real-time messaging (WebSocket)
- Self-booking portal
- Staff assignment
- Docker multi-stage builds
- Prisma schema + seed

api/src/app.module.ts

@@ -0,0 +1,25 @@
+import { Module } from '@nestjs/common';
+import { ClientsModule } from './clients/clients.module';
+import { PetsModule } from './pets/pets.module';
+import { ServicesModule } from './services/services.module';
+import { BookingsModule } from './bookings/bookings.module';
+import { InvoicesModule } from './invoices/invoices.module';
+import { MessagesModule } from './messages/messages.module';
+import { SelfBookingModule } from './self-booking/self-booking.module';
+import { AppController } from './app.controller';
+import { AppService } from './app.service';
+
+@Module({
+  imports: [
+    ClientsModule,
+    PetsModule,
+    ServicesModule,
+    BookingsModule,
+    InvoicesModule,
+    MessagesModule,
+    SelfBookingModule,
+  ],
+  controllers: [AppController],
+  providers: [AppService],
+})
+export class AppModule {}