v0.10.2

Added

• CI: GitHub Actions now runs the full test suite on every push to main and every PR
  (.github/workflows/tests.yml) — 228 tests, Python 3.11 to match the Docker base image, pip
  dependency caching. The test suite has existed for a while but nothing ran it automatically;
  now a red check on a PR means something needs a look before merge. Status badge added to the
  top of the README, alongside the license badge.
• CONTRIBUTING.md updated to mention the automated check.