fix(ui): make modal layouts intrinsic

Pin Iced 0.15 so dialogs can measure content before distributing the resolved frame across child panels. Keep the web plugin notice compact and non-resizable.\n\nCloses #582

src/ui/mod.rs

@@ -2,6 +2,23 @@
 /// Change this to scale the ribbon, layer manager rows, and property panel rows uniformly.
 pub const ROW_H: f32 = 26.0;
 
+/// Iced 0.15 separates pick-list construction from the selection callback.
+/// Keep the application's established call shape while the rest of the UI
+/// migrates independently.
+pub fn pick_list<'a, T, L, V, Message>(
+    options: L,
+    selected: Option<V>,
+    on_select: impl Fn(T) -> Message + 'a,
+) -> iced::widget::PickList<'a, T, L, V, Message>
+where
+    T: PartialEq + Clone + ToString + 'a,
+    L: std::borrow::Borrow<[T]> + 'a,
+    V: std::borrow::Borrow<T> + 'a,
+    Message: Clone + 'a,
+{
+    iced::widget::pick_list(selected, options, |value| value.to_string()).on_select(on_select)
+}
+
 /// Place `content` at fixed top-left coordinates inside a fill-sized layer.
 /// Negative coordinates clamp to the layer edge.
 pub fn pin_at<'a, Message: 'a>(