feat: jukebox corner prop materializing with the ceremony

feat: duck-head modal logo, input lockout mid-roll, quieter quack

feat: modal logo artwork + sync colour variants from pollen site

feat: HUD UX pass - state label with slot-machine roll, keycap hints, per-device highlighting, quack sound from the runtime

feat: standalone Microduck RL playground (MuJoCo WASM + ONNX policies)

initial commit