The file is minstrel-<UTC stamp>.tar: manifest.json first, then
tables/<table>.jsonl, rows one per line in primary-key order. The run's
time lives only in the manifest and member headers are fixed, so a
deduplicating off-site copy stores unchanged tables once.
WriteFile writes to a hidden .part file, syncs it and renames it, so a
watched folder never shows half a backup. Read refuses anything that
isn't a whole backup: another format, a newer format version, a cut-off
file, or a member holding fewer rows than the manifest says.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
