Scratch: - Radial drag around platter center (atan2 angular delta) - Modulates playback speed (-3x to 3x) based on drag direction - Release returns to normal speed or pauses - Visual rotation follows actual speed including reverse Controls: - Left/right arrows: speed/stretch (pitch fader style) - Up/down arrows: seek - Z: reset to 1x speed Also skip dot-prefixed files (._ metadata from macOS) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>