Task 555: Add planetary orbit circles to full-route 3D scene

Status: DONE

Summary

Added orbital path circles for all 5 planets (Mars, Jupiter, Saturn, Uranus, Earth) in the

full-route 3D viewer. Previously only moon orbit circles were drawn in local scenes.

Changes

1. Added OrbitCircleData interface and orbitCircles field to SceneData
2. prepareFullRouteScene now generates orbit circles with correct AU-to-scene radii and z heights
3. Renderer draws semi-transparent orbit circles at each planet's ecliptic height
4. Updated orbital-3d.html example to match

Tests added (5 new)

• orbital-3d-viewer-data.test.ts: orbit circles for 5 planets, radii ordering, AU_TO_SCENE match
• orbital-3d-viewer.test.ts: 5 orbit circles present with positive radii and colors

Files changed

• ts/src/orbital-3d-viewer-data.ts — OrbitCircleData type, orbitCircles in SceneData, populate in prepareFullRouteScene
• ts/src/orbital-3d-viewer-data.test.ts — 3 new tests (28→31)
• ts/src/orbital-3d-viewer.test.ts — 2 new tests (43→45)
• ts/src/orbital-3d-viewer.js — addFullRouteOrbitCircle renderer, render in loadScene
• ts/examples/orbital-3d.html — orbitCircles generation

Impact

• Stats: 4,026 TS tests
• Human directive phase 29 item (2) addressed: planetary orbits now visible