fix: add error handling for missing root element in main.tsx

src/main.tsx

@@ -7,7 +7,12 @@ import App from "./App";
 
 const convex = new ConvexReactClient(import.meta.env.VITE_CONVEX_URL as string);
 
-createRoot(document.getElementById("root")!).render(
+const rootElement = document.getElementById("root");
+if (!rootElement) {
+	throw new Error("Root element not found");
+}
+
+createRoot(rootElement).render(
 	<StrictMode>
 		<ConvexAuthProvider client={convex}>
 			<App />