`npm install`'ed codex is not recognized

Because the foreground process is `node`:

<img width="177" height="88" alt="Image" src="https://github.com/user-attachments/assets/d4ff7a3c-e6f7-43d8-9198-5d4bd354082e" />

Further information:

```
❯ head -n 4 $(which codex)
#!/usr/bin/env node
// Unified entry point for the Codex CLI.

import { spawn } from "node:child_process";
```

How do we solve this?