Board: t21 to Review with its report; new tasks t29, t33-t36; board updates

- t21 report and subtasks ticked.
- New Todo tasks: t33 telling solid ground from loose grains, t34 nozzle blow reach, t35
  diagonal screw tubes, t36 diagonal wall blocks with a sloped face; t29 added on the board.
- The owner's board edits since the last board commit.

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

tasks/t33_make_solid_ground.md

@@ -0,0 +1,17 @@
+---
+id: t33
+title: Make solid ground easy to tell apart from loose grains on top of it
+status: Todo
+created: 2026-10-25
+updated: 2026-10-25T02:04:28Z
+---
+
+## Context
+
+- When loose material (rubble, dirt, ore) lies on top of or against solid rock, the two are hard to tell apart in the smooth look: the loose grains blend into the rock under them, so it's unclear where the solid ground starts and what is still to dig. The owner's screenshot: `/home/aaron/Pictures/Screenshots/Screenshot_20261024_214546.png` (a dug-out area around the bot where loose copper-coloured rubble covers the rock).
+
+## Subtasks
+
+- [ ] Find what makes them blend (similar colours, lighting, the smooth look's edge blending, no outline between loose and solid)
+- [ ] Give loose grains and solid ground a clear visual difference (for example an edge or shading on solid rock, a different texture or brightness for loose grains), in both looks
+- [ ] Check it in dark caves, under the bot's lamp, and with the thermal lens