# Pull Request

## What this changes

<!-- One or two sentences. -->

## Type of change

<!-- Pick one or two. -->

- [ ] 📓 New notebook or lesson
- [ ] 🐛 Bug fix (broken code, typo, dead link)
- [ ] 📚 Docs (README, MDX, comments)
- [ ] ✨ Improvement to existing notebook
- [ ] 🌍 Translation
- [ ] 🔧 Build / config / CI

## Linked issue

<!-- "Fixes #123" or leave blank for small fixes. -->

## How I tested this

<!-- For code: did cells execute top-to-bottom? Which Python version? Any data/keys needed? -->
<!-- For docs: did you check the rendered output on the site? -->

## Checklist

- [ ] Notebook outputs cleared (unless the output is the lesson)
- [ ] If I edited `jupyter-notebooks/`, I ran `python3 scripts/sync_notebooks.py`
- [ ] If I added a phase or top-level route, I ran `python3 scripts/generate_meta_sequential.py`
- [ ] Any new dependencies added to `pyproject.toml` (and the relevant `requirements-*.txt`)
- [ ] Links work; relative links to other phases use the live-site URL or the `jupyter-notebooks/` path

## Notes for reviewers

<!-- Anything unusual, follow-ups, or specific things to double-check. -->
