Initial commit: Full project structure

- Backend: NestJS with Docker
- Frontend: Next.js with Docker
- Nginx configuration for reverse proxy
- PostgreSQL setup
- Docker compose for orchestration
- Development environment configuration

backend/src/app.service.ts

@@ -0,0 +1,8 @@
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class AppService {
+  getHello(): string {
+    return 'Hello World!';
+  }
+}