feat(kb): bass play schema — degree-based patterns with typed approach notes (task C-41)
Key-agnostic bass plays (piano-recipe language): deg XOR typed
approach (chrom-below/above, fifth-of-next — pitch derived from the
next station, never authored), octave 0-1 with a 19-semitone cap
(exactly fret 15 on E-A-D-G), root rule, terminal approaches,
non-decreasing beats, MIN_PLAYS_BASS=1. Legacy BASS_TOKENS stub
replaced (zero references). Smoke 849/849 with 13 new checks;
sabotage-proven twice (author + gate, different malformations).
Ride-along: SCHEMA documents the resolveDegree 7-on-6-chords quirk.
Critic PASS.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
vadimwit
996218f39c