Automatic semantic versioning

[chrislupp]

Is your feature request related to a problem? Please describe.
It is too easy to accidentally miss a version number in the code base. Missing that change can lead to widespread confusion.

Describe the solution you'd like
We should adopt automatic versioning.

Describe alternatives you've considered
N/A

Additional context
None.

[chrislupp]

Closing as completed. Automatic semantic versioning is now handled by the label-driven release workflow (.github/workflows/release.yaml), which bumps the version in pyproject.toml, updates the changelog, creates signed tags, and publishes to PyPI — all automatically on merge.