UI scenarios, batch 2: edit an early sketch from the timeline, components with a revolute joint driven to 90°, sheet metal base and edge flange to flat pattern and DXF, STEP export, new design and STEP insert with a hole on the imported face, parameters table drives the model, sketch constraints workflow (dimensions, delete and undo, fix, construction), rectangular pattern. Harness: widgets found by their text through the accessibility tree, file pickers answered from the scenario's folder, model renders at shot steps (SOLVECRAFT_SCENARIO_SHOTS), query/file checks; ui.at takes a dimension. Fix: a click on a sketch point under a dimension line (a diameter through the centre) selects the point; only the dimension's text takes precedence

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

docs/control-protocol.md

@@ -36,7 +36,7 @@ Commands never open dialogs when run this way. `solvecraft-cli commands` prints
 | `ui.triad` | | screen points of the 3D sketch move triad's handles (`x`, `y`, `z`, `plane`) |
 | `ui.sketchToScreen` | `points`: `[[x, y]…]` in active-sketch coordinates | their screen points (null when behind the camera) |
 | `ui.dialogInput` | `index` | what clicking an input's Select chip does: picks go to that input |
-| `ui.at` | `world: [x,y,z]` \| `sketch: [x,y]` \| `plane: "XY"` \| `axis: "Z"` | the screen point (a scenario step's target; see `crates/ui-egui/src/scenario.rs`) |
+| `ui.at` | `world: [x,y,z]` \| `sketch: [x,y]` \| `plane: "XY"` \| `axis: "Z"` \| `dimension: "d1"` (its value text) | the screen point (a scenario step's target; see `crates/ui-egui/src/scenario.rs`) |
 | `ui.editFeature` | `feature` (id or name) | what double-clicking a timeline item does: rolls back to it and opens its dialog filled in (sketches open in sketch mode) |
 | `ui.scroll` | `x`, `y`, `delta?` | wheel zoom at the cursor |
 | `ui.key` | `key` (egui key name, `Enter`, `Escape`…), `cmd?`, `shift?` | |