iter(g32): tree 补 ↑↓/Home/End 行间导航

packages/skin/ui/src/tree.ts

@@ -72,9 +72,22 @@ export function tree(props: TreeProps): HTMLElement {
     }
   });
 
+  /*** 当前可见的节点行（收起分支的子节点不参与 ↑↓ 遍历） ***/
+  const visibleRows = (): HTMLElement[] =>
+    Array.from(root.querySelectorAll<HTMLElement>('.ua-tree-row')).filter((el) => !el.closest('.ua-tree-children[hidden]'));
+
   root.addEventListener('keydown', (e: KeyboardEvent) => {
     const row = (e.target as HTMLElement).closest('.ua-tree-row') as HTMLElement | null;
     if (!row) return; // 卫语句：焦点不在节点行
+    if (e.key === 'ArrowDown' || e.key === 'ArrowUp' || e.key === 'Home' || e.key === 'End') {
+      const list = visibleRows();
+      const at = list.indexOf(row);
+      if (at < 0) return; // 卫语句：行已不在可见集
+      e.preventDefault();
+      const next = e.key === 'Home' ? list[0] : e.key === 'End' ? list[list.length - 1] : list[at + (e.key === 'ArrowDown' ? 1 : -1)];
+      next?.focus(); // 行间移动只改焦点，不改变选中
+      return;
+    }
     const key = [...rows.entries()].find(([, el]) => el === row)?.[0];
     if (!key) return; // 卫语句：找不到对应节点
     const node = findNode(props.nodes, key);