a25e61ce57
Without --atomic, git push can succeed for the tag ref and fail for the main ref on a non-fast-forward, leaving an orphaned tag at the pre-bump commit. The orphan then trips the 'Tag already exists on origin' guard on the next re-run, requiring manual tag deletion to unblock. --atomic makes the multi-ref push succeed-or-fail as a unit. Caught by Greptile as P1.