QA targets for the newest UX reports (pending until their owners land): s37 browser chevrons on every node kind (all toggle; no Joints folder yet), s38 view animations to Top/Bottom end without a jump (the last frame turns 22.5 degrees today), s39 view cube edge/corner hover lights 2/3 patches, s40 toolbar Pin/Remove/reorder survive a restart and the workspace switcher spans the toolbar; ui_layout tests: every command dialog docked right at 260-380 px (or 480-560 for tables; the exploded view is 635), other windows fit on screen. Harness: published rects and counts, browser rows/fold arrows as handles, camera and view_anim steps, ui.at cube points, settings carried over a close restart, an adhoc scenario runner

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

crates/ui-egui/src/control.rs

@@ -264,6 +264,12 @@ pub fn handle(app: &mut SolveApp, ctx: &egui::Context, req: &ControlRequest) ->
                 };
             }
             let Some(rect) = app.viewport.rect else { return err("no viewport") };
+            if let Some(c) = p.get("cube") {
+                // A point on the view cube, in cube units (faces at ±1).
+                let n = |i: usize| c.get(i).and_then(Value::as_f64).unwrap_or(0.0);
+                let q = crate::viewport::cube_point(app, rect, solvecraft_engine::geom::Vec3::new(n(0), n(1), n(2)));
+                return ok(json!([q.x, q.y]));
+            }
             let proj = crate::viewport::projection(app, rect);
             let num = |v: &Value, i: usize| v.get(i).and_then(Value::as_f64).unwrap_or(0.0);
             let world = if let Some(w) = p.get("world") {