tests/ground_fill_test.ludic compares gg_json (gf_hash over fixed inputs, Math.lerp cases whose order
matters, the yaw as model.vert turns by it, a hand-written density, one cover chunk with a clearing and
one solid chunk) line for line with tests/ground_fill_golden.json, and checks ground_fill draws exactly
the candidates and a solid layer's far bands a subset of band 0. The golden is written by
tests/gen/ground_fill_golden.ludic, run from the repository root; it is not committed here.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
