Fix production worker isolation headers

src/core/plugins/plugin-runner.ts

@@ -115,7 +115,16 @@ function runPluginInWorker<TOptions>(
     const onError = (e: ErrorEvent) => {
       cleanup();
       discardPluginWorker(plugin, worker);
-      reject(new Error("Worker error: " + e.message));
+      const location = e.filename
+        ? ` (${e.filename}${e.lineno ? `:${e.lineno}:${e.colno}` : ""})`
+        : "";
+      reject(
+        new Error(
+          `Worker failed to load or execute${location}: ${
+            e.message || "check worker, CORS, and cross-origin isolation headers"
+          }`
+        )
+      );
     };
 
     context.signal.addEventListener("abort", onAbort);