Port of the blueberry crunch: the popover's LED scope taken edge-to-edge as an immersive full-screen mode. - VisualizerOverlay.swift / VisualizerCapture.swift: the wall itself — dark glass, live waveform, no chrome. Play routes through the instrument while it's up; Escape exits; real pointer movement dismisses it screensaver-style (grace period + travel threshold + re-anchor so a resting hand doesn't fire it); scroll stays pitch-bend/octave, not a dismissal. - WaveformStripView: setCellGeometry(step:size:) scales the LEDs up for full-screen; off-grid paints as one batched fill (offRects) instead of a screen-sized bitmap blit 30×/sec; phosphor-decay fade on the sweep. - Triggers: tap the popover waveform strip (repointed from the keymap), RIGHT ⌘ ×3, and a showVisualizer distributed-notification hook. - Gesture: replace the double-right-⌘ focus/enable gesture with an ALTERNATING left/right ⌘ triple (accepts R-L-R and L-R-L within 0.5s). The two gestures are disjoint on the same key pair. (Blueberry's separate "reverse dub" RewindVoice WIP was NOT pulled in.)