Use whenever an open PR needs shepherding to a merge — watching CI, weighing the agentic reviews, resolving merge conflicts, and merging once everything is green. Assumes the PR already exists (code is written, pushed, and `gh pr create` has run); this skill starts from there. Used by the `build-feature` skill's last step, and by any agent (e.g. a dedicated babysitter) whose job is watching a PR through to landing.