Move the #264 toolbar scroll test into the shared tests/it binary

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/tests/it/main.rs

@@ -42,6 +42,7 @@ mod send_window;
 mod shared_controls;
 mod shortcuts;
 mod side_lists_access;
+mod toolbar_scroll;
 mod toolbar_tempo;
 mod track_height;
 mod track_list;

crates/ui-egui/tests/it/toolbar_scroll.rs

@@ -1,4 +1,5 @@
-// Regression test for #264: the Edit toolbar clipped its tools in a narrow window; it now scrolls horizontally.
+//! Regression test for #264: the Edit toolbar clipped its tools in a narrow window; it now scrolls horizontally.
+
 use egui::{Event, Pos2, Shape, vec2};
 use serde_json::json;
 use soundcraft_ui_egui::{Services, SoundApp};