Loose grains and solid ground look different: a seam on the rock, pebbly lighter grains (t33)

- Smooth look: natural ground gets a soft seam where loose grains meet it; packed grains keep a
  pebble texture and are slightly lighter. Pixel look and thermal lens: the same idea per pixel.
- play.py: the F-on-a-mold toast check records toasts the key press makes instead of counting
  the ones on screen, which failed when an older toast expired at the same moment.

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

docs/agent-log.md

@@ -4,6 +4,19 @@ What agents have done, newest first. Add an entry for every piece of work: the d
 note or request it was for, what changed, the files touched, the tests run, and anything left
 open or not verified. Keep each entry short; the git history has the details.
 
+## 2026-10-25: t33: loose grains and solid ground look different (Claude Code, Codex)
+
+- Smooth look (`src/render/smooth-shaders.js`): natural ground gets a soft seam where it meets
+  loose grains as well as air; packed grains keep the pebble shading and are slightly lighter.
+  Pixel look and thermal lens (`drawWorld()` in `src/render/world.js`): loose grains a touch
+  lighter and speckled, solid cells touching loose grains darker.
+- Smooth frame 1.08 -> 1.10 ms. `t_smooth.py` checks the seam and the lighter grains;
+  `tools/scenes/t33-ground.js` for screenshots (`shots/t33/`).
+- play.py: 'F on an automatic ingot mold stays quiet' counted toasts on screen, and failed
+  now and then when an older toast expired or a new one arrived in the same 150 ms; it now
+  records the toasts the key press makes (none). `run_all.py --browser` ALL PASSED apart from
+  that check, which passes in the new form.
+
 ## 2026-10-25: t37: buildings cast no shadows (Claude Code, Codex)
 
 - `computeLight()` (`src/render/light.js`): a per-view-column light roof that skips player-built