Fix handling of terminal columns

[131]

Summary

• handle undefined/zero column widths when spawned without TTY
• adjust bundle column handling for same case
• provide eslint.config.js so npm test works with new ESLint

Testing

• npm test

---

https://chatgpt.com/codex/tasks/task_e_684039c43598833190a73ab261c0c29a

[coveralls]

coverage: 85.311% (-0.7%) from 86.0%
when pulling 29e833b on codex/trouver-et-corriger-un-bug
into f2753ec on master.

[131]

I'd rather go with a Math.min(Math.max(X, 0), ...) to make sure the value is positive rather than a ternary