Merge branch 'backend-setup' into main

backend/src/app.module.ts

 import { Module } from '@nestjs/common';
+import { ConfigModule } from '@nestjs/config';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
 
 @Module({
-  imports: [],
+  imports: [ConfigModule.forRoot()],
   controllers: [AppController],
   providers: [AppService],
 })

backend/src/main.ts

@@ -4,8 +4,9 @@ import { AppModule } from './app.module';
 
 async function bootstrap(): Promise<void> {
   const app = await NestFactory.create(AppModule);
-  const configService = new ConfigService();
-  const port = configService.get('PORT');
+  const configService = app.get(ConfigService);
+
+  const port = configService.get<number>('PORT');
   console.log(`NestJS server is listening on: http://localhost:${port}`);
   await app.listen(port);
 }