iter(g44): accordion 标题行方向键导航

packages/skin/ui/src/accordion.ts

@@ -51,5 +51,25 @@ export function accordion(props: AccordionProps): HTMLElement {
     ),
   );
 
-  return h('div', { class: 'ua-accordion' }, ...rows);
+  const root = h('div', { class: 'ua-accordion' }, ...rows);
+
+  // —— 键盘导航：↑↓ 行间环形移动、Home/End 首尾直达，均跳过禁用行（对齐 tabs/tree 约定） ——
+  const heads = (): HTMLButtonElement[] => rows.map((r) => r.firstElementChild as HTMLButtonElement); // 各行标题按钮
+  const focusFrom = (start: number, dir: 1 | -1): void => {
+    const len = heads().length;
+    for (let n = 1; n <= len; n++) {
+      const cand = heads()[(((start + dir * n) % len) + len) % len]; // 环形取候选：越界回绕保证落在 [0, len)
+      if (!cand.disabled) { cand.focus(); return; } // 跳过禁用行，绕满一圈即止
+    }
+  };
+  root.addEventListener('keydown', (e: KeyboardEvent) => {
+    const list = heads();
+    const idx = list.indexOf(document.activeElement as HTMLButtonElement);
+    if (idx < 0) return; // 卫语句：焦点不在标题行
+    if (e.key === 'ArrowDown' || e.key === 'ArrowUp') { e.preventDefault(); focusFrom(idx, e.key === 'ArrowDown' ? 1 : -1); }
+    else if (e.key === 'Home') { e.preventDefault(); focusFrom(-1, 1); }   // 从头正向找第一个可用
+    else if (e.key === 'End') { e.preventDefault(); focusFrom(0, -1); }    // 从尾反向找最后一个可用
+  });
+
+  return root;
 }