Task 570: Fix ring/plane geometry rotation bug in 3D viewer

Status: DONE

Summary

Ring and tilted plane geometry had incorrect orientation because:

1. Normal vectors weren't y/z swapped for Three.js coordinate system
2. Ring had an extra -90° X rotation compounding with the quaternion

Root cause

• Data normals are in scene coords (x,y,z) but Three.js uses Y-up (swaps y/z)
• addRing() computed quaternion from unswapped normal then added extra rotateX
• addTiltedPlane() computed quaternion from unswapped normal
• addAxis() already correctly swapped y/z (line 408) — inconsistency

Fix

• Both addRing() and addTiltedPlane() now swap y/z before quaternion computation
• Removed extra rotateX(-Math.PI/2) from ring rendering
• Now consistent with addAxis() y/z swap pattern

Files changed

• ts/src/orbital-3d-viewer.js — fixed addRing and addTiltedPlane normal handling

Impact

• Saturn ring plane and Uranus equatorial plane now correctly oriented