Use Next.js standalone output for lean production runtime.

Deploy can drop full node_modules and run .next/standalone/server.js (~100MB RSS).

next.config.ts

@@ -1,6 +1,8 @@
 import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
+  // Leaner production runtime: deploy uses .next/standalone and drops node_modules.
+  output: "standalone",
   images: {
     remotePatterns: [
       {