Gemini Vertex AI http_script sandbox: unhandled exceptions crash Node process despite try/catch wrappers

When using new Function() to execute agent-generated JavaScript attack scripts in a CTF benchmark harness, unhandled exceptions from async functions defined inside the script crash the entire Node.js process. The script wrapper uses try { ... } catch(e) { return error } but async functions called without await inside the script body produce floating promise rejections that escape the wrapper. The most common crash pattern: the script calls res.json() on a non-JSON response (e.g. HTML error page), which throws a TypeError that propagates as an unhandled rejection.