Make Iris layout dependencies explicit

app-rust/src/ui/mod.rs

@@ -445,7 +445,7 @@ where
     // The wheel handler here is identical to the helper's; only the drag
     // differs, and it arrives through `Selection::drag`, which hands
     // committed pans and releases to this same span.
-    list.on(CursorSense::Scroll, |ctx, rsc| {
+    list.on(CursorSense::Scroll(Axis::Y), |ctx, rsc| {
         let delta = ctx.data.scroll_delta.y * 50.0;
         ctx.widget(rsc).scroll(delta);
     })