Summary

• Add JSRemote convenience APIs for @JSClass bridged objects.
• Add an async withJSObject body overload so remote JS object access can await promises on the owning thread.
• Keep sync and async remote invocation storage separate, preserve worker executor affinity where available, and hide async body APIs for Embedded multithreaded builds.
• Add worker-to-main and main-to-worker tests covering async remote bodies that await JavaScript promises.