Add release pipeline workflow triggered on version tags that builds
wheel and Docker image, creates Forgejo releases with artifacts.
Add uv caching to CI pipeline for faster builds. Add status-check
consolidation job for branch protection. Update CONTRIBUTING.md
with CI/CD documentation covering pipeline overview, required
checks, and release process.
Also fixes pre-existing test failures discovered during full nox
suite verification.
ISSUES CLOSED: #858
brent.edwards