Poetry/pytest/ruff/black/mypy config mirroring the aio extension lint
pipeline (spirekeeper template). `make test` runs pytest; `make check`
runs the linters. Enables a tests/ suite for the extension.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019VUQCfdqiLSsFS2jcGnaFD
