# hdiff-update-core
Core primitives for signed HDiffPatch directory updates.
The crate provides:
- strict managed-path and Windows reparse-point validation;
- canonical per-file SHA-256 tree manifests;
- Ed25519 release signing and verification;
- atomic patch downloads;
- HDiffPatch directory creation and replay wrappers;
- persistent staging transactions with verified reuse.
It never patches a live installation and never downloads a full installer.
Applications delegate full-update fallback to their normal updater.
HDiffPatch binaries are not embedded. Release tooling supplies `hdiffz` and the
application packages `hpatchz`.