fix: use server code from webhook response for location select value

The stats webhook now returns a 'code' field (e.g. 'fr', 'usa')
alongside the display 'server' name. The option value now uses
s.code and falls back to slugified server name for backward compat.

assets/js/script.js

@@ -669,10 +669,11 @@ async function initServerLocations() {
 
     servers.forEach(function (s) {
       const server = s.server || "";
+      const serverCode = s.code || server.toLowerCase().replace(/\s+/g, "-");
       const available = parseInt(s["Seats Available"], 10) || 0;
       const label = server.charAt(0).toUpperCase() + server.slice(1);
       const opt = document.createElement("option");
-      opt.value = server.toLowerCase().replace(/\s+/g, "-");
+      opt.value = serverCode;
 
       if (available <= 0) {
         // No seats — red, disabled, cannot select