feat: TOC as separate Aero Window on desktop

components/table-of-contents.tsx

@@ -35,7 +35,7 @@ export default function TableOfContents({ headings }: TableOfContentsProps) {
   if (headings.length === 0) return null;
 
   return (
-    <nav className="bg-white/20 backdrop-blur border border-white/30 rounded-lg p-4 lg:sticky lg:top-8">
+    <nav>
       <p className="text-xs font-bold uppercase tracking-widest text-blue-800 mb-3">
         Contents
       </p>