Entire

Map context.Canceled to NewSilentError so Ctrl-C exits quietly instead of printing a noisy Cobra error (matches the clean.go convention). [cursor]
When the user confirms push but checkpoint pushing is disabled in settings, report that the refs stay queued instead of "Pushed 0 checkpoint ref(s)". [cursor]
Add a --remote flag (default origin) instead of hardcoding "origin", so repos that push to a different remote work. [copilot]
MigrateBranchToRefs now only uses an existing ref as the new commit's parent when it resolves to a real commit; a ref at an unreadable/non-commit object is treated as absent (orphan) rather than parenting on a bad hash, which would corrupt the commit graph for fetch+replay. [copilot]

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com Entire-Checkpoint: 5d352fa1b1bb

migrate-checkpoints: address review (silent cancel, disabled push, --remote, parent validation)