fullsend-ai metrics

Definitions: Defect rate = fix PRs linked to an issue with a defect label (bug, defect, regression, incident, production-bug, or type: bug) ÷ merged PRs. This is an explicit-label proxy; it does not prove preventability or distinguish a review-escaped bug from a missed requirement. Revert rate = PRs titled Revert ... or typed subjects such as fix: revert ..., plus Git commits containing This reverts commit; duplicate evidence and temporary changes reverted within the same merged PR are excluded. These are GitHub signals—not DORA Change Failure Rate, which requires production deployment and rollback/hotfix data.