Squash of 5 work commits (Sep 2–9):
066c782 piano model: the lower register is hammered, not plucked
f2b0253 drumkit: a sample-based kit for the score preview; the physical model parked as drumkit_phys
3dfe5aa show-control: restore sixteen DMX scenes with local save overlays
b49e2e5 piano-model: calibrate partial gains and decay against recordings
d73cd40 piano_model: add an interactive piano-physics explainer page
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
