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

k-tv-frontend/app/(main)/layout.tsx

@@ -1,12 +1,12 @@
 import Link from "next/link";
 import { type ReactNode } from "react";
 import { NavAuth } from "./components/nav-auth";
+import { AdminNavLink } from "./components/admin-nav-link";
 
 const NAV_LINKS = [
   { href: "/tv", label: "TV" },
   { href: "/guide", label: "Guide" },
   { href: "/dashboard", label: "Dashboard" },
-  { href: "/admin", label: "Admin" },
   { href: "/docs", label: "Docs" },
 ];
 
@@ -33,6 +33,9 @@ export default function MainLayout({ children }: { children: ReactNode }) {
                   </Link>
                 </li>
               ))}
+              <li>
+                <AdminNavLink />
+              </li>
             </ul>
             <div className="ml-2 border-l border-zinc-800 pl-2">
               <NavAuth />