iter(g86): 弹层外部点击监听改按需挂载

packages/skin/ui/src/cascader.ts

@@ -1,6 +1,6 @@
 import { effect, h, signal } from '@ui-arch/frame';
 import type { Signal } from '@ui-arch/frame';
-import { pushOverlay } from './overlay.js';
+import { bindOutside, pushOverlay } from './overlay.js';
 import { flip } from './position.js';
 import type { CascaderOption, CascaderProps } from './types.js';
 
@@ -132,10 +132,7 @@ export function cascader(props: CascaderProps): HTMLElement {
     if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); btn.click(); } // 与鼠标点击同语义
   });
 
-  document.addEventListener('click', (e) => {
-    if (root.contains(e.target as Node)) return; // 卫语句：组件内点击不处理
-    open(false); // 点外部收起
-  });
+  bindOutside(root, open, () => open(false)); // 点外部收起：仅展开期间挂监听，收起即摘
   effect(render); // 依赖 open / path / value，任一变化即重绘
   effect(() => {
     if (open()) releaseEsc ??= pushOverlay(() => { open(false); trigger.focus(); }); // 入栈：与弹窗/抽屉共用逐层关闭