Surgical fixes (originals preserved in history), each documented in the
per-model run notes as: where the bug is, pre-fix behavior, root cause,
with the shown build being the fixed one:
- grok-build: 0xAETHER invalid hex literal killed the script at parse
time (pure black screen); atlas flipY mismatch made near terrain
sample undrawn black texels. 2 lines.
- composer-2-5: horizontal movement multiplied dt twice, walking at
~1/60 design speed and making biomes effectively unreachable. 1 line.
- gpt-5-5-pro: 8x2 atlas rows swapped by default flipY, grass became
obsidian and leaves/sand sampled undrawn slots. 1 line.
Gemini 3.5 Flash added as-is (color/transparency analysis next).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>