The blind foot-plant broadcast hit every entity-registered component; mixers
whose authored OUTPUT control is Start forwarded the send as a Start and fired
their sound on every stride (the per-step ProgramButton 'chirp'). Added
GetOutputControlID() to AudioControlMixer/Multiplier and the broadcast now
feeds only stages outputting Volume(3)/Brightness(5) -- the footstep loudness
inputs -- directly (mixers are entity-registered, no splitter hop needed).
Verified: FootFallInt01 delivers on BOTH gaits now (11/run, walk input included);
ProgramButton deliveries 188 -> 38 (the remainder are authored looped-sequence
cockpit ambience, not the broadcast); stable 28s drive+fire.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
