devx/docs/specs/DEVX-179.md

DEVX-179: auto-merge must never select [skip ci] squash titles

Problem

PR #351 squash-merged as DEVX-178: chore: update badge URLs to commit 4422c70b [skip ci]. extract_conventional_msg picked a commit subject carrying [skip ci] — a master badge commit surfaced in the PR's commit list after force-push/amend rewrote branch history. The resulting merge commit suppressed the post-merge push run: no release, no publish, no wiki sync, no Vikunja close.

PR #352 shows the secondary defect: two ci: commits on the branch and the older one won the tie, so the squash title described a throwaway retrigger commit instead of the real change.

Approach

REQ-1: Subjects containing [skip ci], [ci skip], or [skip actions] (case-insensitive) are ineligible merge titles. They are excluded before priority scoring, so a badge/chore/[skip ci] commit can never suppress the post-merge pipeline again.

REQ-2: Equal-priority ties resolve to the newest commit in the returned list (Gitea returns PR commits newest-first; iterate in returned order and keep the first best candidate).

Test Plan

• test_auto_merge.py: commits [ci retrigger, badge-chore-skipci] → the ci subject wins; commits [older-ci, newer-ci] → newest wins; all commits [skip ci] → falls back to newest non-skipped subject.
• make pytest-cov (100% gate), make lint-all.

Deploy Plan

Merge as fix: → post-merge cuts a release that also ships DEVX-178's PLAYBOOK_ROLE_MAP entry.

Rollback Plan

Revert the squash commit; extract behavior returns to the previous (unhardened) selection.

Acceptance Criteria

• REQ-1: [skip ci]/[ci skip]/[skip actions] subjects are never selected.
• REQ-2: Equal-priority ties pick the newest commit.
• Unit tests cover both; 100% coverage maintained.