Drops the 12 zodiac PNGs, their loader/similarity-transform renderer and
the art anchors in constellations.js; build_constellations.py no longer
emits art data. Constellation mode now shows just the Stellarium traces,
labels and stars.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015HtPHsTnDcLVSCiF5FGHZj
