feat: conditionally inject Cloudflare Analytics script

- Updated index.html to include a placeholder for Cloudflare Web Analytics, which is now only injected in production mode.
- Modified vite.config.ts to implement an HTML transform plugin that dynamically adds the Cloudflare script based on the environment.

index.html

@@ -65,8 +65,8 @@
     <div id="root"></div>
     <script type="module" src="/src/main.tsx"></script>
 
-    <!-- Cloudflare Web Analytics -->
-    <script defer src='https://static.cloudflareinsights.com/beacon.min.js' data-cf-beacon='{"token": "2aecdc025eb043bc89ce931b54a80054"}'></script>
+    <!-- Cloudflare Web Analytics - Only in Production -->
+    <!--CLOUDFLARE_ANALYTICS_PLACEHOLDER-->
     <!-- End Cloudflare Web Analytics -->
   </body>
 </html>