Fix stale force-push wording in prePushCheckpointRefs doc
Commit

The git-refs pre-push path was switched to fast-forward-only pushes with fetch+replay recovery; the doc comment still said "batch force-pushes". Wording only — no behavior change.
Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com Entire-Checkpoint: f758baeca44c
Checkpoints
Checkpoint 1