fix: make output export build-only so dev route handlers work

next.config.ts

@@ -1,8 +1,12 @@
-import type { NextConfig } from 'next'
+import type { NextConfig } from 'next';
+
+const isExport = process.env.NODE_ENV === 'production';
 
 const nextConfig: NextConfig = {
-  output: 'export',
+  /* output: 'export' only applies at build time — enabling it in dev mode
+   * breaks route handlers (incompatible with force-dynamic in Next.js 16) */
+  ...(isExport ? { output: 'export' } : {}),
   images: { unoptimized: true },
-}
+};
 
-export default nextConfig
+export default nextConfig;