High-res tiles also in 128x128 for close views

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

art/generated/textures/PROMPTS.md

@@ -63,3 +63,14 @@ Molten lava seen from above, glowing orange and yellow molten rock flowing in sw
 Water and lava flow as before (the shader moves the texture along the river and lets the surface
 swell); in the high-res style a second, larger layer of the same texture drifts slower and
 sideways over it, so the surface churns.
+
+## 128x128 (2026-11-07)
+
+The same raw pictures also give 128x128 tiles for close views (`HD_TILE2`; the world shows them
+when a tile gets nearly 128 pixels, else the 64x64 ones):
+
+```bash
+python3 tools/make_tile.py <name>-raw.png <name> --size 256 --colors 48 --band 28
+```
+
+`<name>-256.png` is copied to `assets/textures/<name>-256.png`.