The mergemaster pipeline used git merge --ff-only to apply the squash
commit from a merge-queue branch onto master. This raced with the
filesystem watcher which auto-commits pipeline file moves to master,
causing the fast-forward to fail. The mergemaster agent would then
improvise by manually moving stories to done without the code merge.
- Replace --ff-only with cherry-pick so concurrent watcher commits
don't block the merge
- Add report_merge_failure MCP tool for explicit failure handling
- Update mergemaster prompt to forbid manual file moves
- Fix cleanup_merge_workspace to handle stale directories
Squash merge of feature/story-205
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
81065a3ada