Fix hosted MapLibre demo API base and missing Three core module.

This vendors three.core.js required by latest three.module.js and defaults the demo API base to window.location.origin when no local override is saved.

Made-with: Cursor

web/maplibre-demo.js

@@ -647,4 +647,8 @@ const savedBase = localStorage.getItem("geo_api_base");
 if (savedBase) {
   apiBaseEl.value = savedBase;
   setClientBase(savedBase);
+} else {
+  const defaultBase = window.location.origin;
+  apiBaseEl.value = defaultBase;
+  setClientBase(defaultBase);
 }