Fresh-eyes review of the glow-up found the G5 side-ring texture applied to
whole tier cylinders - linear UVs on the caps rendered as diagonal stripes
across the disc. CylinderGeometry takes [side, top, bottom] materials: sides
keep Lane E's ring texture, caps get a new radial recordCapGrooveTexture()
(machines/util.ts) with ring count scaled per tier radius so groove pitch
stays constant. Also lands the three handoff-doc updates from the phase.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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