Checkpoint: Initial stable CheckFlow base before i18n and demo mode

next.config.ts

@@ -1,7 +1,16 @@
 import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
-  /* config options here */
+  output: "standalone",
+  // PWA service worker (manual - no next-pwa needed)
+  async headers() {
+    return [
+      {
+        source: "/manifest.json",
+        headers: [{ key: "Content-Type", value: "application/manifest+json" }],
+      },
+    ];
+  },
 };
 
-export default nextConfig;
+export default nextConfig;