Fix: sketch edit exit (double-click a sketch no longer traps you)

Edit Sketch rolls the timeline back to just after the sketch and faces it;
Finish Sketch, Esc (once nothing else is left to cancel) and editing another
feature all leave it, restoring the marker and the previous view. Editing the
open sketch again is a no-op and editing another sketch switches cleanly.
The control channel's ui.click takes double: true.

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

crates/ui-egui/src/sketch_edit_tests.rs

@@ -0,0 +1,71 @@
+//! Regression tests: editing a sketch from the Browser or timeline can always be left again.
+
+use crate::{Services, SolveApp};
+use solvecraft_engine::Session;
+use solvecraft_engine::doc::FeatureKind;
+
+fn sample_app() -> SolveApp {
+    let mut s = Session::default();
+    s.run_script(&solvecraft_engine::sample::script()).unwrap();
+    SolveApp::new(s, Services::default())
+}
+
+fn first_sketch(app: &SolveApp) -> u64 {
+    app.session.doc.features.iter().find(|f| matches!(f.kind, FeatureKind::Sketch { .. })).map(|f| f.id).unwrap()
+}
+
+#[test]
+fn edit_sketch_rolls_back_and_finish_restores() {
+    let mut app = sample_app();
+    let marker = app.session.doc.marker;
+    let id = first_sketch(&app);
+    app.edit_sketch(id);
+    assert_eq!(app.session.active_sketch, Some(id));
+    let idx = app.session.doc.feature_index(id).unwrap();
+    assert_eq!(app.session.doc.marker, Some(idx + 1), "later features are rolled back");
+    app.finish_sketch();
+    assert_eq!(app.session.active_sketch, None);
+    assert_eq!(app.session.doc.marker, marker, "marker restored");
+}
+
+#[test]
+fn editing_twice_does_not_nest() {
+    let mut app = sample_app();
+    let marker = app.session.doc.marker;
+    let id = first_sketch(&app);
+    app.edit_sketch(id);
+    app.edit_sketch(id);
+    app.edit_feature(id);
+    app.finish_sketch();
+    assert_eq!(app.session.active_sketch, None);
+    assert_eq!(app.session.doc.marker, marker);
+}
+
+#[test]
+fn editing_another_sketch_switches_cleanly() {
+    let mut app = sample_app();
+    let marker = app.session.doc.marker;
+    let ids: Vec<u64> = app.session.doc.features.iter().filter(|f| matches!(f.kind, FeatureKind::Sketch { .. })).map(|f| f.id).collect();
+    app.edit_sketch(ids[0]);
+    app.edit_sketch(ids[1]);
+    assert_eq!(app.session.active_sketch, Some(ids[1]));
+    app.finish_sketch();
+    assert_eq!(app.session.active_sketch, None);
+    assert_eq!(app.session.doc.marker, marker);
+}
+
+#[test]
+fn toolbar_finish_and_other_feature_edit_leave_the_sketch() {
+    let mut app = sample_app();
+    let marker = app.session.doc.marker;
+    let id = first_sketch(&app);
+    app.edit_sketch(id);
+    app.start("SketchStop");
+    assert_eq!(app.session.active_sketch, None);
+    assert_eq!(app.session.doc.marker, marker);
+    // Double-clicking a solid feature while sketching finishes the sketch first.
+    app.edit_sketch(id);
+    let extrude = app.session.doc.features.iter().find(|f| !matches!(f.kind, FeatureKind::Sketch { .. })).map(|f| f.id).unwrap();
+    app.edit_feature(extrude);
+    assert_eq!(app.session.active_sketch, None);
+}