feat: establish backend foundation

src/main.ts

@@ -1,8 +1,31 @@
 import { NestFactory } from '@nestjs/core';
+import { ConfigService } from '@nestjs/config';
+import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
 import { AppModule } from './app.module';
+import { HttpExceptionFilter } from './common/filters/http-exception.filter';
+import { Environment } from './config/env.validation';
+import { shouldExposeSwagger } from './config/swagger.config';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
-  await app.listen(process.env.PORT ?? 3000);
+  const config = app.get<ConfigService<Environment, true>>(ConfigService);
+  const frontendOrigin = config.getOrThrow<string>('FRONTEND_ORIGIN');
+
+  app.enableCors({ origin: frontendOrigin });
+  app.setGlobalPrefix('api/v1');
+  app.useGlobalFilters(new HttpExceptionFilter());
+
+  if (shouldExposeSwagger(process.env['NODE_ENV'])) {
+    const document = SwaggerModule.createDocument(
+      app,
+      new DocumentBuilder()
+        .setTitle('WealthLedger API')
+        .setVersion('v1')
+        .build(),
+    );
+    SwaggerModule.setup('api/docs', app, document);
+  }
+
+  await app.listen(config.getOrThrow('PORT'));
 }
-bootstrap();
+void bootstrap();