Add GPT-5.5 Pro/xhigh and Gemini 3.5 Flash runs; fix three artifacts

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>

outputs/grok-build/mythos-craft.html

@@ -79,7 +79,7 @@
     const CHUNK_SIZE = 16;
     const CHUNK_HEIGHT = 128;
     const VIEW_DISTANCE = 5; // chunks in each direction
-    const WORLD_SEED = 0xAETHER;
+    const WORLD_SEED = 0xAE7E12; // fix: original `0xAETHER` is not a valid hex literal (T/H/R), which killed the whole script at parse time
 
     // Block IDs
     const BLOCK = {
@@ -361,6 +361,7 @@
       drawCrystal(7, 1);
 
       const texture = new THREE.CanvasTexture(canvas);
+      texture.flipY = false; // fix: tiles are drawn from the canvas top, but UVs assume a top-left origin; with default flipY=true every face sampled the undrawn (black) bottom rows of the atlas
       texture.magFilter = THREE.NearestFilter;
       texture.minFilter = THREE.NearestFilter;
       texture.wrapS = texture.wrapT = THREE.RepeatWrapping;