Source snapshot

This book was built from the following commit of cashubtc/nuts. If something here disagrees with upstream, upstream wins.

commit 1363de413294e2ef3a57b16950f9506af38fffc2
Author: Rob Woodgate <robwoodgate@users.noreply.github.com>
Date:   Fri Oct 23 19:03:23 2026 +0100

    Merge pull request #402 from robwoodgate/nut28-htlc-example
    
    tests: add NUT-28 HTLC example proof