[Shellghostt]

Refs #1 — the upload itself happens from the tag after this merges.

What

Bumps the first PyPI release to 0.3.1 (the existing v0.3.0 tag points at an older commit, so the tag-driven workflow needs a new tag):

• webvac/__init__.py → 0.3.1 (the single source of truth for the build)
• CHANGELOG.md → 0.3.1 entry covering the PyPI install path, tests, CI, Docker, CONTRIBUTING, and the Python 3.11 report fix
• README.md → current release and highlights
• docs/RELEASE_CHECKLIST.md → example tag updated to v0.3.1

Verification

$ python -m build
Successfully built webvac-0.3.1.tar.gz and webvac-0.3.1-py3-none-any.whl

$ python -m twine check dist/*
Checking dist/webvac-0.3.1-py3-none-any.whl: PASSED
Checking dist/webvac-0.3.1.tar.gz: PASSED

$ python -m pytest tests -q
43 passed

After merge (user)

1. Add a pending trusted publisher at https://pypi.org/manage/account/publishing/ with: project webvac, owner Shellghostt, repo WebVac, workflow release.yml, environment blank.
2. Push v0.3.1 (or ask me to). The Release workflow builds, checks, and publishes via OIDC.
3. Verify pip install webvac in a clean venv, then close Publish WebVac to PyPI #1.