Hide the Next.js dev-mode route indicator badge

Sets devIndicators: false in next.config.ts. Compile/runtime error
overlays are unaffected - only the floating route-info badge is hidden.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/next.config.ts

@@ -1,5 +1,8 @@
 import type { NextConfig } from "next";
 
-const nextConfig: NextConfig = {/* config options here */};
+const nextConfig: NextConfig = {
+  // Hides the on-screen dev-mode route indicator badge. Compile/runtime error overlays still show.
+  devIndicators: false,
+};
 
 export default nextConfig;