Add Cloudflare Web Analytics beacon (production origin only)

Author: rgilks

lobby_worker/index.html

@@ -230,5 +230,15 @@ <h1 class="game-title">PONGO</h1>
     </div>
     <script type="module" src="pwa.js"></script>
     <script type="module" src="script.js"></script>
+    <!-- Cloudflare Web Analytics: anonymous visit counts, production origin only. -->
+    <script>
+      if (location.hostname.endsWith("tre.systems")) {
+        const beacon = document.createElement("script");
+        beacon.defer = true;
+        beacon.src = "https://static.cloudflareinsights.com/beacon.min.js";
+        beacon.setAttribute("data-cf-beacon", '{"token": "893eaee1dc1d46109119d2b54cdf023e"}');
+        document.head.appendChild(beacon);
+      }
+    </script>
   </body>
 </html>