run_js_ephemeral
Run a JavaScript snippet in a temporary disposable container with optional npm dependencies, then automatically clean up.
The code must be valid ESModules (import/export syntax). Ideal for simple one-shot executions without maintaining a sandbox or managing cleanup manually.
When reading and writing from the Node.js processes, you always need to read from and write to the "./files" directory to ensure persistence on the mounted volume.
This includes images (e.g., PNG, JPEG) and other files (e.g., text, JSON, binaries).
Example:
```js
import fs from "fs/promises";
await fs.writeFile("./files/hello.txt", "Hello world!");
console.log("Saved ./files/hello.txt");
```