feat: admin provider UI (types, hooks, guard, settings panel, conditional admin nav)

k-tv-frontend/app/(main)/components/admin-nav-link.tsx

@@ -0,0 +1,17 @@
+"use client";
+
+import Link from "next/link";
+import { useCurrentUser } from "@/hooks/use-auth";
+
+export function AdminNavLink() {
+  const { data: user } = useCurrentUser();
+  if (!user?.is_admin) return null;
+  return (
+    <Link
+      href="/admin"
+      className="rounded-md px-3 py-1.5 text-sm text-zinc-400 transition-colors hover:bg-zinc-800 hover:text-zinc-100"
+    >
+      Admin
+    </Link>
+  );
+}