X and the toolbar's Construction no longer start a pick tool (Fusion has none): with a selection they convert it, with nothing selected they switch construction mode, outside a sketch they say so. Center Rectangle draws both diagonals as construction, the centre at their crossing, with only the first carrying the midpoint constraint (the second is implied), so a fresh one stays at 4 DOF. Scenarios s30 (pattern a hole) and s32 (cut in the active component) enabled now that b36b332 is on main

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

crates/ui-egui/src/lib.rs

@@ -420,8 +420,8 @@ impl SolveApp {
             }
         }
         // Construction toggle: selected sketch curves switch at once, otherwise pick them.
-        // Construction (X): convert the selection, or switch construction mode.
-        if id == "sketch.construction" && self.session.active_sketch.is_some() {
+        // Construction (X): convert the selection, or switch construction mode; no pick tool.
+        if id == "sketch.construction" {
             sketch_palette::toggle_construction(self);
             return;
         }

crates/ui-egui/src/sketch_palette.rs

@@ -75,7 +75,9 @@ pub fn set_mode(app: &mut SolveApp, m: u8) {
 /// switch construction mode on or off.
 pub fn toggle_construction(app: &mut SolveApp) {
     let curves = selected_curves(app);
-    if curves.is_empty() {
+    if curves.is_empty() && app.session.active_sketch.is_none() {
+        app.set_status("Construction mode is for drawing in a sketch: edit a sketch first", false);
+    } else if curves.is_empty() {
         let m = if mode(app) == 1 { 0 } else { 1 };
         set_mode(app, m);
     } else {

crates/ui-egui/src/tools.rs

@@ -65,7 +65,6 @@ impl Tool {
             "ConstraintCollinear" => ("ConstraintCollinear", Kind::Pick(2)),
             "ConstraintMidPoint" => ("ConstraintMidPoint", Kind::Pick(2)),
             "ConstraintSymmetry" => ("ConstraintSymmetry", Kind::Pick(3)),
-            "sketch.construction" => ("sketch.construction", Kind::Pick(1)),
             _ => return crate::sketch_tools::tool_for(id),
         };
         Some(Tool { cmd, kind, pts: Vec::new(), hover: None, picks: Vec::new(), dims: Vec::new(), dims_stage: usize::MAX, dims_focus: false })
@@ -280,7 +279,6 @@ fn run_pick(app: &mut SolveApp, t: &Tool) {
     let params = match t.cmd {
         "ConstraintHorizontalVertical" => json!({"line": k[0]}),
         "ConstraintFix" => json!({"entity": k[0]}),
-        "sketch.construction" => json!({"curves": [k[0]]}),
         "ConstraintCoincident" => json!({"a": k[0], "b": k[1]}),
         "ConstraintMidPoint" => json!({"point": k[0], "line": k[1]}),
         "ConstraintSymmetry" => json!({"a": k[0], "b": k[1], "line": k[2]}),