extension.CheckNote, NewNote and Note apply the rules of spec v0.11 24.1,
and extension.Standard registers the note for the noncritical array of
PUBLIC_HEADER only. Header.PublicNote reads it, and header_binding ties it to
the control: a note changed after writing fails step 15. The CLI writes it
with -note and shows it as text of the creator, with the warning that nobody
can check it before the date.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
