Mirror the voicing field for the two deferred FEP #24 harmony annotations on
ChordTemplate:
- caged: str ("C"/"A"/"G"/"E"/"D", "" = unset)
- guideTones: list[int] (semitone offsets 0..11 above the root, [] = unset)
Both are default-omitted on the wire and sanitized on decode (caged enum-guarded,
guideTones filtered to in-range ints, rejecting bool) so a malformed value can't
round-trip. GP import is untouched — GP carries no CAGED / guide-tone data.
Teaching annotations only; never fed to a grader.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>