feat(admin): add custom page title 'Hördle Admin Dashboard'

app/admin/layout.tsx

@@ -0,0 +1,14 @@
+import type { Metadata } from "next";
+
+export const metadata: Metadata = {
+    title: "Hördle Admin Dashboard",
+    description: "Admin dashboard for managing songs and daily puzzles",
+};
+
+export default function AdminLayout({
+    children,
+}: {
+    children: React.ReactNode;
+}) {
+    return <>{children}</>;
+}