Fix Select Base UI parity regressions

.changeset/match-select-base-ui-behaviour.md

@@ -0,0 +1,8 @@
+---
+'@gpuix/react': patch
+---
+
+Match Select with Base UI when items have no explicit value, when keyboard
+navigation changes the active item, and when items are removed from the list.
+Preserve group and label accessibility semantics and report the correct missing
+ItemText context.

README.md

@@ -3666,8 +3666,19 @@ so item content can reflect its current state. `Select.ItemText` accepts the
 same function child; it renders with the current item state while the label
 used by the trigger and typeahead comes from the unhighlighted, unselected
 call. Item `label` and `textValue` props override that function-derived label.
-Arrow Up/Down, Home/End and typeahead keep the highlighted item in view. Pointer
-hover updates the highlight without changing the popup's scroll position.
+`Select.Root`'s `itemToStringLabel` resolves object values for the closed
+trigger; without it, values with `label` or `value` fields use those fields.
+`Select.Popup` supplies the listbox role when no `Select.List` is rendered;
+with a `List`, the role belongs to the list and the trigger does not set
+`aria-controls`.
+Opening the popup focuses the selected item, and closing it returns focus to
+the trigger.
+Arrow Up/Down, Home/End and typeahead move focus with the highlighted item and
+keep it in view. Arrow Down on a closed trigger opens the popup; the next arrow
+press moves through the items. Pointer hover updates the highlight without
+changing the popup's scroll position. If a selected item is removed from the
+list, a single Select returns to its initial value when that item remains;
+multiple Select removes values whose items are no longer present.
 
 ### Build a local Select
 
@@ -3793,6 +3804,8 @@ the trigger. Disabled items are skipped. The highlighted item scrolls into
 view, and scroll arrows appear only while the list can scroll further in that
 direction. Home/End and PageUp/PageDown are not handled.
 
+`onOpenChangeComplete` runs after the requested open state has rendered.
+
 Select parts accept `className` and `style` functions with state matching the
 corresponding Base UI part. `Root` renders no element and takes neither prop.
 When a part accepts `render={<element />}`, the element's `className` is kept