Sync from marionette-experimental: host-shell architecture + everything since 2026-05-19 r4

tests/scripts: dance playback comparison (python_native vs marionette_style)

Sync from marionette-experimental: flicker fix, share/community repairs,

Trim intro.mp3 to 3 s to match the wiggle motion length

Swap intro.wav → intro.mp3 (benkirb-shine-10-268906, 4.66 s)

Startup plays a real recorded move (intro.json + intro.wav)

Add daemon control script with SIGINT shutdown