feat(layers): alphabetical default order + scroll to a new layer

The Layer Manager table and the ribbon's quick layer dropdown both
showed layers in document (insertion) order. Default the panel sort to
Name so both list layers alphabetically; a header click still re-sorts
by any other column. `apply_sort` reorders the panel's layer vector in
place, which the ribbon dropdown reads, so one default covers both.

With alphabetical ordering a freshly created layer can land anywhere in
a long list, so give the table scrollable an id and scroll its row into
view after creation, keeping the rename prompt visible.

Closes #270, closes #271

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/update/command.rs

@@ -635,7 +635,23 @@ pub(super) fn on_tab_close(&mut self, idx: usize) -> Task<Message> {
                     self.tabs[i].layers.edit_buf = new_name.clone();
                 }
                 self.sync_ribbon_layers();
-                Task::none()
+                // With alphabetical ordering (#270) the new layer can land
+                // anywhere in a long list; scroll its row into view so the
+                // rename prompt is visible (#271). Offset is layout-independent
+                // (idx × fixed row height), so it holds even before the freshly
+                // added row is measured.
+                match new_idx {
+                    Some(idx) => iced::widget::operation::scroll_to(
+                        iced::advanced::widget::Id::new(
+                            crate::ui::window::layers::LAYER_TABLE_SCROLL_ID,
+                        ),
+                        iced::widget::scrollable::AbsoluteOffset {
+                            x: 0.0,
+                            y: idx as f32 * crate::ui::ROW_H,
+                        },
+                    ),
+                    None => Task::none(),
+                }
     }
 
     pub(super) fn on_layer_delete(&mut self) -> Task<Message> {