lib/git/import.sx parses loose payloads back to native objects bottom-up
over an export-set table: tree mode/name/raw-sha triples, ident lines,
header/message split, committer stored only when distinct so export
defaults regenerate identical bytes. Laws verified: export->import->export
is BYTE-IDENTICAL (head sha + every object), imported blobs/default-mode
trees regain their original native cids, 100755/tags/distinct-committer/
multi-line messages all survive. 15/15, total 267/267.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>