feat: bootstrap he maintainer skill

he-maintainer/references/python.md

@@ -0,0 +1,33 @@
+# Python Harness Notes
+
+Use this reference for Python repositories.
+
+## Common files to inspect
+
+- `pyproject.toml`
+- `requirements.txt`
+- `poetry.lock`
+- `uv.lock`
+- `src/`
+- `tests/`
+- `tox.ini`
+- `noxfile.py`
+
+## Common validation commands
+
+Typical examples:
+
+- `pytest`
+- `ruff check .`
+- `mypy .`
+- `python -m build`
+- `tox`
+
+Prefer environment-specific commands already documented by the repo.
+
+## Common guardrails
+
+- avoid mixing package managers in guidance
+- be explicit about virtualenv or tool runner if required
+- note when tests depend on services, fixtures, or secrets
+- prefer local, minimal edits over package-wide rewrites