Night-butterfly identity over pop/lib/preview-shared: YWFT IMAB title bounce, section progress strip with tints, chord letters riding an 8-bar scrolling mini-DAW (seven lanes, real audio waveform inside every event block), fixed-center playhead, section-tinted wings breathing with the RMS envelope. Form mirrored from hitbaker.mjs. 1920x1080@30 -> out/imab-hitbaker-demo1-track.mp4. Claude-Session: https://claude.ai/code/session_01LaRrW1RHanS8it7SzgrqeV