pub fn load_map_inverse(
dir: &Path,
) -> Result<HashMap<Sha1Id, Hash>, BridgeError>Expand description
Load the map inverted (sha1 → blake3) for the import direction.
Parsed directly from the file lines: translation is many-to-one
(two historic-mode spellings of a tree normalize to ONE mkit
tree), so inverting the blake3-keyed load_map would drop a
sha1 and force a pointless re-translation every fetch.