feat: import native road packages from ZIP

scripts/lib/native-preview-traffic-simulation.js

@@ -19,7 +19,8 @@ const DEFAULT_SETTINGS = {
 };
 
 function buildNativeTrafficSimulation(area, options = {}) {
-  const root = area.outputs.nativeRoadDir;
+  const root = options.nativePackage?.rootDir;
+  if (!root) throw new Error("Native traffic simulation requires an imported native road package");
   const compiledPath = path.join(root, "compiled.json");
   const signalPath = path.join(root, "traffic-signals.json");
   const connectorPath = path.join(root, "layers", "connectors.geojson");