Add premerge_baseline_proof.py distinguishing four validation outcomes
(clean pass / current-master failure reproduced / pre-merge baseline-proven
failure / unresolved regression risk). A non-zero exit may only be labeled
"baseline"/"pre-existing" with pre-merge proof: the failure reproduced on the
PR's pre-merge base commit, or a documented known-failure record predating the
PR. Current-master (post-merge) reproduction is explicitly rejected as
sufficient baseline proof.
- premerge_baseline_proof.py: assess_premerge_baseline_proof + labels
- final_report_validator.py: reviewer.premerge_baseline_proof rule on
review_pr and reconcile_already_landed tasks
- skills/llm-project-workflow/templates/review-pr.md: baseline proof section
requiring base commit, tested commit, command, exit status, failure signature
- tests/test_premerge_baseline_proof.py: reject current-master-only proof,
accept pre-merge base proof and documented known-failure records
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
