Fix: handle non-array response for streams in App.jsx (prevent crash on rate-limiting)

client/src/App.jsx

@@ -271,7 +271,7 @@ export default function App() {
     try {
       const res = await fetch(`${API_BASE}/api/streams`);
       const data = await res.json();
-      setStreams(data);
+      setStreams(Array.isArray(data) ? data : []);
     } catch (e) {
       console.error('Failed to fetch streams:', e);
     }