fix(ink): restore host prop updates in React 19 reconciler (#589)

React 19's react-reconciler@0.33 mutation path calls commitUpdate with
(instance, type, oldProps, newProps, fiber), but our Ink host config
still expected an updatePayload from prepareUpdate. That left mounted
ink-* nodes with stale onKeyDown, tabIndex, and textStyles, making menu
navigation and highlights appear stuck until remount.

Diff old/new props directly inside commitUpdate and add regression tests
covering in-place updates for ink-box handlers/attributes and ink-text
styles.

src/ink/reconciler.ts

@@ -449,17 +449,25 @@ const reconciler = createReconciler<
   },
   commitUpdate(
     node: DOMElement,
-    updatePayload: UpdatePayload | null,
     _type: ElementNames,
-    _oldProps: Props,
-    _newProps: Props,
+    oldProps: Props,
+    newProps: Props,
   ): void {
-    if (!updatePayload) {
+    // React 19 mutation mode calls commitUpdate as
+    // (instance, type, oldProps, newProps, fiber) and does not pass the
+    // prepareUpdate() payload here. This renderer used to treat the second
+    // argument as updatePayload, which left mounted ink-* nodes with stale
+    // attributes, event handlers, and textStyles until something forced a
+    // remount. Recompute the prop/style diff here so host nodes update
+    // correctly in place on rerender.
+    const props = diff(oldProps, newProps)
+    const style = diff(oldProps['style'] as Styles, newProps['style'] as Styles)
+    const nextStyle = newProps['style'] as Styles | undefined
+
+    if (!props && !style) {
       return
     }
 
-    const { props, style, nextStyle } = updatePayload
-
     if (props) {
       for (const [key, value] of Object.entries(props)) {
         if (key === 'style') {