
## Summary
Explain what this PR changes and why.

## Type of change
- [ ] Bug fix
- [ ] New feature
- [ ] Refactor / cleanup
- [ ] Docs only
- [ ] CI / tooling

## How to test
- Commands / scripts to run:
```

pytest -q
ruff check .
ruff format --check .
mypy

```
- If it touches physics, include a quick before/after plot or metric (e.g., growth rate).

## Checklist
- [ ] Code follows style (Ruff) and types (MyPy)
- [ ] Tests added or updated
- [ ] Docs updated (README / examples / docstrings)
- [ ] Backwards compatible (or migration noted)

## Related issues
Closes #<issue-number> (if applicable)

## Notes for reviewers
Anything you want reviewers to pay special attention to.
