merge: 合并 GitHub 远程更改并优化 serverless 配置

- 合并本地和远程的 api/index.ts 配置
- 使用 ExpressAdapter 提升 serverless 性能
- 保留全局过滤器和拦截器
- 保留 body-parser 大文件支持
- 统一 CORS 配置

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/index.ts

@@ -1,19 +1,31 @@
 import { NestFactory } from '@nestjs/core';
-import { AppModule } from '../src/app.module';
+import { ExpressAdapter } from '@nestjs/platform-express';
+import { AppModule } from '../dist/app.module';
 import { HttpExceptionFilter } from '../src/common/filters/http-exception.filter';
 import { TransformInterceptor } from '../src/common/interceptors/transform.interceptor';
 import { ValidationPipe } from '@nestjs/common';
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
+import * as express from 'express';
 import * as bodyParser from 'body-parser';
 
-let cachedApp;
+// 缓存 app 实例，避免每次冷启动都重新创建
+let cachedApp: any;
 
 async function bootstrap() {
   if (!cachedApp) {
-    const app = await NestFactory.create(AppModule);
+    const expressApp = express();
+    const app = await NestFactory.create(
+      AppModule,
+      new ExpressAdapter(expressApp),
+    );
 
+    // 配置 CORS
     app.enableCors({
-      origin: true,
+      origin: [
+        'https://tradingadvfrontend.vercel.app',
+        'http://localhost:8000',
+        'http://localhost:3030',
+      ],
       credentials: true,
       methods: ['GET', 'POST', 'PUT', 'DELETE', 'PATCH', 'OPTIONS'],
       allowedHeaders: [
@@ -26,8 +38,11 @@ async function bootstrap() {
       ],
     });
 
+    // 全局过滤器和拦截器
     app.useGlobalFilters(new HttpExceptionFilter());
     app.useGlobalInterceptors(new TransformInterceptor());
+
+    // 全局验证管道
     app.useGlobalPipes(
       new ValidationPipe({
         whitelist: true,
@@ -36,12 +51,13 @@ async function bootstrap() {
       }),
     );
 
+    // Body parser 配置
     app.use(bodyParser.json({ limit: '50mb' }));
     app.use(bodyParser.urlencoded({ limit: '50mb', extended: true }));
 
-    // Swagger 配置
+    // Swagger 文档
     const config = new DocumentBuilder()
-      .setTitle('我的应用 API')
+      .setTitle('API 文档')
       .setDescription('这是我的应用程序的 API 文档')
       .setVersion('1.0')
       .addBearerAuth()
@@ -50,14 +66,13 @@ async function bootstrap() {
     SwaggerModule.setup('api', app, document);
 
     await app.init();
-    cachedApp = app;
+    cachedApp = expressApp;
   }
-
   return cachedApp;
 }
 
-export default async (req, res) => {
+// Vercel Serverless handler
+export default async function handler(req: any, res: any) {
   const app = await bootstrap();
-  const server = app.getHttpAdapter().getInstance();
-  return server(req, res);
-};
+  app(req, res);
+}