Allow use within legacy node project

Question

If I run within a legacy node project with Node version less than 18, I get: `Error: Claude Code requires Node.js version 18 or higher.`

It would be great to be able to specify which Node binary to use with an environment variable. Currently I'm using this wrapper script to accomplish something similar:

```sh
#!/bin/sh

if [[ -n "$NODE_BINARY" ]]; then
	exec env PATH="$(dirname $NODE_BINARY):$PATH" claude "$@"
fi

exec claude "$@"
```