补强 UI 预览测试清理

为预览测试统一注册 afterEach cleanup，避免测试间残留 DOM。

保留原有 UI 选择与拖拽交互行为。

apps/ai-game-creator-shell/tests/uiEditorPreview.test.tsx

@@ -1,7 +1,7 @@
 // @vitest-environment jsdom
 
-import { fireEvent, render, screen } from '@testing-library/react';
-import { describe, expect, it, vi } from 'vitest';
+import { cleanup, fireEvent, render, screen } from '@testing-library/react';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 
 import type { Node as UiNode } from '../src/features/ui-editor/types/Node';
 import type { UITree } from '../src/features/ui-editor/types/UITree';
@@ -9,6 +9,10 @@ import { ExclusiveChildrenTabs } from '../src/view/ui-editor/components/preview/
 import { UiTreeRenderer } from '../src/view/ui-editor/components/preview/UiTreeRenderer';
 import { UiNodeContextMenu } from '../src/view/ui-editor/components/UiNodeContextMenu';
 
+afterEach(() => {
+  cleanup();
+});
+
 function node(id: string, children: UiNode[] = []): UiNode {
   return {
     id,
@@ -286,7 +290,7 @@ describe('UI tree preview visibility', () => {
   it('uses a highlighted tab bar for exclusive child switching', () => {
     const parent = exclusiveNode('parent', [node('child-a'), node('child-b')]);
     const onSelectChild = vi.fn();
-    const rendered = render(
+    render(
       <ExclusiveChildrenTabs
         parent={parent}
         isChildVisible={(nodeId) => nodeId === 'child-a'}
@@ -306,7 +310,6 @@ describe('UI tree preview visibility', () => {
     ).toBe('false');
     fireEvent.click(screen.getByRole('tab', { name: 'child-b' }));
     expect(onSelectChild).toHaveBeenCalledWith('child-b');
-    rendered.unmount();
   });
 
   it('keeps exclusive tab pointer gestures out of the parent node', () => {