Make SolveApp::start honour a command's enabled flag, and disable solid.move inside a sketch (#740)

`SolveApp::start` now honours a command's enabled flag, so shortcuts, the command palette and the control channel can't start a disabled command, and Move is disabled while a sketch is open.

crates/ui-egui/src/control.rs

@@ -137,6 +137,7 @@ pub fn handle(app: &mut SolveApp, ctx: &egui::Context, req: &ControlRequest) ->
             "camera": app.cam,
             "tool": app.tool.as_ref().map(|t| t.cmd),
             "dialog": app.dialog.as_ref().map(|d| format!("{d:?}")),
+            "status": app.status.as_ref().map(|(text, _, error)| json!({"text": text, "error": error})),
             "hover": app.viewport.hover.as_ref().map(|h| format!("{h:?}")),
             "renderer": if app.viewport.gpu.is_some() { "gpu" } else { "cpu" },
             "frame_ms": app.frame_ms,

crates/ui-egui/src/lib.rs

@@ -530,6 +530,16 @@ impl SolveApp {
         if self.file_load.busy() {
             return;
         }
+        // A disabled command starts nothing, however it was reached. The toolbar greys its
+        // button, but a shortcut, the command palette and the control channel all land here.
+        // Its reason goes to the status line, so the refusal is never silent.
+        if let Some(info) = solidcraft_engine::find_command(id).map(|c| c.info(&self.session))
+            && let Some(why) = info.disabled_reason
+        {
+            let label = self.tr_label(info.label).to_string();
+            self.set_status(format!("{label}: {why}"), true);
+            return;
+        }
         // Another command ends Edit Text (its dialog is not a feature edit to keep).
         sketch_text_move::cancel_drag(self);
         if sketch_text::editing(self) || self.dialog.as_ref().is_some_and(|d| matches!(d.kind, dialogs::Kind::TextMove(_))) {

crates/ui-egui/src/scenario.rs

@@ -34,6 +34,7 @@
 //! - `{"note": "…"}`: a comment; `{"pending": "why"}`: the scenario waits for a fix (its test
 //!   is ignored)
 //! - `{"expect": {…}}`: checks, see [`check`]; `{"until": {…}}` waits (frames) until they pass
+//!   (`"status"` takes a substring of the status line, or null for none)
 //!
 //! The same files drive the live app over the control channel for screenshots.
 
@@ -562,7 +563,8 @@ fn approx(got: f64, want: &Value, what: &str) -> Result<(), String> {
 
 /// Checks: `bodies` (count), `volume` / `area` (total, number or [value, rel tol]), `faces`,
 /// `features` (count), `errors` (timeline features in error, default 0), `dialog` (null: none
-/// open, or a word its kind must contain), `tool` (null or command id), `sketching` (bool),
+/// open, or a word its kind must contain), `tool` (null or command id), `status` (null, or a
+/// substring of the status line), `sketching` (bool),
 /// `selection` (count), `glyphs` ({constraint id: count}, none overlapping one another or a dimension value), `param` ({name: value}), `sketch_status` (solved|…), `dof`, `query`
 /// ({command, params?, path, value}: a command's result).
 pub fn check(h: &mut Harness, e: &Value) -> Result<(), String> {
@@ -760,6 +762,18 @@ pub fn check(h: &mut Harness, e: &Value) -> Result<(), String> {
                     return Err(format!("tool: got {}, want {v}", ui["tool"]));
                 }
             }
+            "status" => {
+                // A substring of the status line's text, or null for no status at all.
+                let got = &ui["status"]["text"];
+                let ok = match v {
+                    Value::Null => ui["status"].is_null(),
+                    Value::String(w) => got.as_str().is_some_and(|g| g.contains(w.as_str())),
+                    _ => false,
+                };
+                if !ok {
+                    return Err(format!("status: got {}, want {v}", ui["status"]));
+                }
+            }
             "glyphs" => {
                 // {constraint id: glyphs drawn for it}; glyphs never overlap one another.
                 let g = crate::sketch_tools::glyph_positions();