chore(backlog): 记录 g17 完成

.ua/backlog.json

@@ -498,7 +498,7 @@
       "title": "select 键入字母快跳选项",
       "motivation": "选项多时纯方向键逐个移动太慢，主流下拉都支持键入首字母循环跳转",
       "acceptance": "select 展开时键入可打印字符循环聚焦 label 前缀匹配项（不区分大小写），1 秒无输入重置缓冲；既有 ↑↓/Home/End 行为不变；npm run check 全绿",
-      "status": "open",
+      "status": "done",
       "notes": "自补：既有组件可用性细节"
     }
   ]

.ua/iterations.log

@@ -61,3 +61,4 @@
 {"ts":"2026-10-26T10:52:00+08:00","id":"g11","result":"done","commit":"00a7b90","summary":"新增 flip() 翻转判定：popover/tooltip/select/menu 打开时按视口空间自动上下翻转，弹层不再溢出被裁切"}
 {"ts":"2026-10-26T10:55:35+08:00","id":"g15","result":"done","commit":"85988f0","summary":"toast 悬停暂停倒计时、移出按剩余时长继续，长文案不再来不及读"}
 {"ts":"2026-10-26T10:58:01+08:00","id":"g16","result":"done","commit":"a036b0a","summary":"image 加载失败自动替换虚线占位块，fallback 可自定义文案，demo 附失效地址示例"}
+{"ts":"2026-10-26T11:00:20+08:00","id":"g17","result":"done","commit":"27d797a","summary":"select 展开后键入字母按前缀环形快跳选项，1s 无输入重置缓冲，既有键盘导航不变"}