Enable Next.js standalone output for leaner production deploys.

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: {
     formats: ["image/avif", "image/webp"],
     // Every quality value used across the page. Required from Next.js 16 on.