pax 8c1266ab0d ci: add GitHub Actions test workflow + README badge
Runs pytest tests/ on every push and PR. Ubuntu runner with
Python 3.11, libmpv, and QT_QPA_PLATFORM=offscreen for headless
Qt. Badge in README links to the Actions tab.

117 tests, ~0.2s locally. CI time depends on PySide6 install
(~2 min) + apt deps (~30s) + tests (~1s).
2026-04-10 00:01:28 -05:00
..