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/browser.rs

@@ -145,7 +145,7 @@ pub fn browser(app: &mut SolveApp, ui: &mut egui::Ui) {
                                 row(ui, "sketch", &name, None, false)
                             };
                             if r.double_clicked() {
-                                let _ = app.run("SketchActivate", json!({"sketch": id}));
+                                app.edit_sketch(id);
                             }
                             r.on_hover_text("Double-click to edit");
                         }