Stage 3. moons.js: 21 moons as lit spheres with local per-parent compression
(clear the exaggerated parent, ordering preserved), retrograde via negative
period. rings.js: Saturn textured annulus (true 74500–140220 km scaled with
parent) + Uranus thin schematic ring, tilted with axial tilt, DoubleSide. Moons
draw at the parent's exaggeration so Io/Jupiter ≈ 0.026 ratio holds. Label
visibility gated via CSS2DObject.visible (CSS2DRenderer clobbers div.style.display
every frame — fixed). Gate: Galilean laps 1.00:0.50:0.25 (1:2:4), Triton
retrograde (Δθ<0), moons ordered io<europa<ganymede<callisto.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
