v0.12.0 pre-publish: version bumping, coverage, badges, PR governance

[davidkhjo]

Pre-publish polish (one PR, batched commits).

Version bumping (single source + one command)

• Version now lives only in src/ebm/__init__.py; hatchling reads it (dynamic = ["version"] + [tool.hatch.version]). No more editing two files.
• Makefile targets: make bump-patch|bump-minor|bump-major bump + commit + tag in one step; make check / make cov shortcuts. Release flow documented in CONTRIBUTING.

Coverage

• pytest-cov + [tool.coverage]; CI runs pytest --cov (currently 95%). No external service (Codecov removed per request) — a static coverage badge plus the live number in CI logs.

README / About

• Six flat badges (CI, PyPI, coverage, Python, downloads, License) and a much simpler two-line description. GitHub "About" shortened.

PR governance

• .github/CODEOWNERS (* @davidkhjo) requests the maintainer's review on every PR.
• The Claude review workflow (from /install-github-app) runs on every PR; branch protection will require CI + Claude + maintainer review before merge (applied after this merges).

Housekeeping

• nia.json gitignored + untracked (local tooling only).

All green locally: ruff, mypy, 103 tests @ 95% cov, ebmkit-0.12.0 builds from the single source, twine check passes.

[davidkhjo]

yes

[davidkhjo]

yes

yes