Improve application performance by enabling stricter rendering checks

Enable React StrictMode in main.tsx to improve application performance and fix import in App.tsx.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: c5f0c281-8dd8-4846-b452-4a07bcd21062
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/9777c70b-fc38-4831-8d6b-78dfffe041b0/b3df3caf-5bc0-43a9-92d9-f6960fd7812e.jpg

client/src/App.tsx

@@ -1,4 +1,3 @@
-import React from "react";
 import { Switch, Route } from "wouter";
 import { queryClient } from "./lib/queryClient";
 import { QueryClientProvider } from "@tanstack/react-query";

client/src/main.tsx

@@ -1,11 +1,11 @@
-import React from "react";
+import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
 import App from "./App";
 import "./index.css";
 import "./i18n/config";
 
 createRoot(document.getElementById("root")!).render(
-  <React.StrictMode>
+  <StrictMode>
     <App />
-  </React.StrictMode>
+  </StrictMode>
 );