Add Vite+React frontend scaffold, update build pipeline, dashboard tweaks

frontend/src/main.tsx

@@ -0,0 +1,10 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import App from './App';
+import './app.css';
+
+ReactDOM.createRoot(document.getElementById('root') as HTMLElement).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);