fix: set __WZP_BASE_URL before loading variant scripts (WASM path resolution)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/crates/warzone-server/src/routes/web.rs

@@ -1711,6 +1711,8 @@ async function loadAudioVariant(variant) {
   if (!file) return null;
 
   try {
+    // Set base URL so variant scripts resolve WASM imports via /audio/ path
+    window.__WZP_BASE_URL = SERVER + '/audio';
     const script = document.createElement('script');
     script.src = SERVER + '/audio/js/' + file;
     await new Promise((resolve, reject) => {