Fix admin sidebar missing on /curator/* routes

- Extract AdminShell component (sidebar + wrapper)
- admin/layout.tsx uses AdminShell
- curator/layout.tsx uses AdminShell for admin role (was rendering children only)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/curator/layout.tsx

@@ -3,15 +3,16 @@ import { auth } from "@/lib/auth";
 import { redirect } from "next/navigation";
 import Link from "next/link";
 import { LogoutButton } from "@/components/layout/logout-button";
+import { AdminShell } from "@/components/admin/admin-shell";
 
 export default async function CuratorLayout({ children }: { children: React.ReactNode }) {
   const session = await auth.api.getSession({ headers: await headers() });
   if (!session) redirect("/login");
   if (session.user.role !== "curator" && session.user.role !== "admin") redirect("/dashboard");
 
-  // Admin uses their own layout — render content only
+  // Admin uses the admin shell with sidebar
   if (session.user.role === "admin") {
-    return <>{children}</>;
+    return <AdminShell userName={session.user.name}>{children}</AdminShell>;
   }
 
   return (