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/t35_diagonal_screw_tubes.md

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+---
+id: t35
+title: Diagonal screw tubes
+status: Todo
+created: 2026-10-25
+updated: 2026-10-25T02:35:19Z
+---
+
+
+
+## Context
+
+- Screw tubes only run straight: up, down, left or right. Add diagonal tubes, and let them be placed diagonally (dragging a line at 45° lays a diagonal run), so grains and bars can be carried up or down a slope without stair-stepping straight pieces.
+
+## Subtasks
+
+- [ ] Decide how a diagonal tube looks and fits the 4×4 block grid (a block per diagonal step, or a dedicated diagonal piece)
+- [ ] Move grains and bars along diagonal tubes, including joining onto and off straight tubes and belts
+- [ ] Placing: dragging at 45° lays a diagonal run; R picks the diagonal directions when placing a single piece
+- [ ] Copy, cut, paste, undo and blueprints handle diagonal tubes
+- [ ] Tests for carrying sand and bars up and down a diagonal run, and for the joins