When a commit fixes a bug introduced by an identifiable prior commit,
the fix should record the offending short SHA in a Regression-of:
trailer at the bottom of the commit message body.
This is a standard Git trailer (parseable by git interpret-trailers)
that makes intra-release regression detection trivial: the release
skill can now read the trailer directly instead of hunting through
git log and git blame to figure out whether a 'Fixed' entry actually
describes a bug a shipped user ever saw.
- AGENTS.md: new 'Attributing Regressions' subsection under Using Git
with the convention, when-to-add/skip rules, and tracing tips.
- .agents/skills/release/SKILL.md: Step 5.2 now has a fast path that
reads Regression-of trailers via 'git log --format=%(trailers:...)',
with the existing manual git log/blame approach as fallback.
- CONTRIBUTING.md: brief mention in the Bug fixes section and a new
self-review checklist item pointing at AGENTS.md.
Alex Gleason