feat: implement SSE real-time frontend updates on new payload reception

src/components/Layout.tsx

@@ -36,6 +36,27 @@ const Layout = () => {
     };
 
     loadInitial();
+
+    // Set up SSE for real-time updates
+    const API_URL = import.meta.env.VITE_API_URL || '/api';
+    const sse = new EventSource(`${API_URL}/stream`);
+    
+    sse.onmessage = (event) => {
+      try {
+        const data = JSON.parse(event.data);
+        if (data.type === 'update') {
+          fetchData().then(newData => {
+            setOrdersData(newData);
+          });
+        }
+      } catch (e) {
+        console.error("SSE parse error", e);
+      }
+    };
+
+    return () => {
+      sse.close();
+    };
   }, []);
 
   useEffect(() => {