feat: publish foreman-orchestrator to PyPI

[ehsantg]

Closes #13

Summary

• CI workflow (.github/workflows/ci.yml) — runs pytest on Python 3.11/3.12/3.13 on every push/PR; uploads coverage to Codecov
• Publish workflow (.github/workflows/publish.yml) — builds sdist + wheel with hatchling, validates with twine check, publishes via PyPI Trusted Publishing (OIDC) — no stored API token; stable v* tags go to PyPI + create a GitHub Release, pre-release tags go to TestPyPI only; publish is gated on the test suite passing
• Dependabot (.github/dependabot.yml) — weekly grouped updates for pip and github-actions
• pyproject.toml — author corrected, Python 3.12/3.13 classifiers added, project URLs added, pytest-cov added to dev extras
• README — static badges replaced with live CI, Codecov coverage, PyPI version/downloads/python-versions badges
• CONTRIBUTING.md (new) — SemVer bump policy documented (MAJOR/MINOR/PATCH), release process, pyproject.toml as single source of truth
• CHANGELOG.md — reformatted to Keep a Changelog with ## [X.Y.Z] - YYYY-MM-DD headers, [Unreleased] section, and comparison links at the bottom for all 21 versions

Acceptance checklist

• Versioning rule (SemVer) documented with a single source of truth (pyproject.toml)
• Publish workflow uses Trusted Publishing (no API token secrets), gated on green tests, with a TestPyPI dry-run path
• dependabot.yml covers pip + github-actions
• A version bump / tag automatically publishes the release and creates a GitHub Release
• README shows live CI status, coverage, and PyPI badges
• CHANGELOG in Keep a Changelog format
• pip install foreman-orchestrator works — one manual step after merge: register a Trusted Publisher on pypi.org/manage/account/publishing pointing to VisionForge-OU/foreman / workflow publish.yml, then push the v0.6.0 tag

Test plan

• Merge PR; verify CI workflow runs green on main
• Register PyPI Trusted Publisher (see above)
• Push git tag v0.6.0-rc1 && git push origin v0.6.0-rc1 — confirm TestPyPI publish succeeds
• Push git tag v0.6.0 && git push origin v0.6.0 — confirm PyPI publish + GitHub Release created
• pip install foreman-orchestrator && foreman --version