- source 8 public-domain equirectangular mosaics (io/europa/ganymede/callisto/
titan/triton/charon/phobos) from usgs astrogeology, downscale to 1024x512 jpg
(0.92 mb added total, each <=143 kb); credits.md lists source/mission/license
- bodies.js: texture field on the 8 sourced moon entries only
- moons.js: load textures via ctx.loadTextureInto (same path as planets.js, so
the moon's own 2k map also renders now); flat-color 404 fallback preserved
- moons.js tick: tidal lock rotation.y = 2pi*(jd-J2000)/period + pi (signed
period gives retrograde spin for free)
