fix: correct NestJS dist output path for Vercel serverless function

Author: konnn04

api/index.ts

@@ -1,8 +1,6 @@
 import type { IncomingMessage, ServerResponse } from 'node:http';
 import serverlessHttp from 'serverless-http';
-// Import from pre-built dist — compiled by `nest build` in vercel-build step
-// eslint-disable-next-line @typescript-eslint/no-require-imports
-const { createApp } = require('../dist/create-app') as { createApp: () => Promise<import('@nestjs/platform-express').NestExpressApplication> };
+import type { NestExpressApplication } from '@nestjs/platform-express';
 
 type ServerlessHandler = (
   req: IncomingMessage,
@@ -13,9 +11,14 @@ let cachedHandler: ServerlessHandler | null = null;
 
 async function getHandler(): Promise<ServerlessHandler> {
   if (!cachedHandler) {
+    const { createApp } = (await import('../dist/src/create-app.js')) as {
+      createApp: () => Promise<NestExpressApplication>;
+    };
     const app = await createApp();
     await app.init();
-    cachedHandler = serverlessHttp(app.getHttpAdapter().getInstance());
+    cachedHandler = serverlessHttp(
+      app.getHttpAdapter().getInstance() as Parameters<typeof serverlessHttp>[0],
+    );
   }
   return cachedHandler;
 }

vercel.json

@@ -1,10 +1,8 @@
 {
   "version": 2,
-  "buildCommand": "pnpm vercel-build",
-  "outputDirectory": ".",
   "functions": {
     "api/index.ts": {
-      "includeFiles": "{dist/**,web-ui/dist/**,node_modules/.prisma/**,node_modules/@prisma/client/**}",
+      "includeFiles": "{dist/src/**,web-ui/dist/**,node_modules/.prisma/**,node_modules/@prisma/client/**}",
       "memory": 1024,
       "maxDuration": 30
     }