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>

tools/scenes/t33-ground.js

@@ -0,0 +1,24 @@
+// Paused dug pocket: copper ore, rubble and dirt against stone, granite and dirt.
+// Use --js "..." to set daylight or R.lens after this setup; CAM frames the pocket.
+const cx = 360, cy = 300;
+for (let y = 0; y < 480; y++) for (let x = 100; x < 620; x++) {
+  const dx = x - cx, dy = y - cy;
+  const floor = 20 + Math.round(3 * Math.sin(dx * 0.11));
+  const wall = Math.abs(dx) > 68 || dy < -42 || dy >= floor;
+  const ground = dx < -23 ? STONE : dx < 23 ? GRANITE : DIRT;
+  let m = wall ? ground : EMPTY;
+  if (!wall && dy > floor - 11 - Math.round(3 * Math.sin(dx * 0.18))) {
+    m = dx < -23 ? RSTONE : dx < 23 ? CUORE : LDIRT;
+    if ((x * 7 + y * 11) % 19 === 0) m = CUORE;
+  }
+  const i = y * W + x;
+  bgm[i] = 0;
+  setCell(i, m, 22, wall ? F_NAT : 0);
+}
+for (let x = 100; x < 620; x++) {
+  surfY[x] = 100; dirtY[x] = 180; graniteY[x] = 400;
+}
+updateRoof();
+window.CAM = [cx, cy];
+SET.daylight = 0;
+SET.lighting = 'full';