Fix: Disk Usage zeigt undefined für TB/PB Werte

Lokale formatBytes Funktion hatte sizes Array nur bis GB.
TB und PB ergänzt.

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

frontend/app/page.tsx

@@ -68,7 +68,7 @@ export default function Dashboard() {
   const formatBytes = (bytes: number) => {
     if (bytes === 0) return "0 B"
     const k = 1024
-    const sizes = ["B", "KB", "MB", "GB"]
+    const sizes = ["B", "KB", "MB", "GB", "TB", "PB"]
     const i = Math.floor(Math.log(bytes) / Math.log(k))
     return (bytes / Math.pow(k, i)).toFixed(1) + " " + sizes[i]
   }