Fix: add favicon to page metadata

frontend/app/layout.js

@@ -9,6 +9,9 @@ const inter = Inter({ subsets: ["latin"] });
 export const metadata = {
   title: "Reduce",
   description: "A simple URL shortener application",
+  icons: {
+    icon: "/favicon.ico",
+  },
 };
 
 export default function RootLayout({ children }) {