v1.0.0

First release, by Louis Wright.

• Required-bump calculation from Conventional Commits since the last release tag (or --base), including ! and BREAKING CHANGE: footers and 0.x semantics.
• Rules: version-regressed, invalid-version, version-not-bumped, insufficient-bump, excessive-bump, version-skipped, prerelease-mismatch, tag-exists, changelog-missing, changelog-no-entry, changelog-empty-entry, changelog-not-latest, changelog-bad-date, unreleased-not-empty, non-conventional-commit.
• CHANGELOG parsing for Keep a Changelog and plain ## x.y.z headings.
• Text/JSON/SARIF/Markdown output, --fail-on, exit codes 0/1/2, allowlist with expiry, severity overrides.
• Composite GitHub Action with job summary.