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.