Folders, all the way down

A folder is a list of files and other folders, each entry named by a BLAKE3 hash; a parent's hash is computed from its children's. That makes the repo a Merkle tree — a structure where one root hash fingerprints everything below it. git is built the same way; mkit just makes it visible: edit any file and watch every hash above it rewrite — file → folder → parent folder → commit.