chore(backlog): 记录 g106 完成

.ua/backlog.json

@@ -1211,7 +1211,7 @@
       "motivation": "affix / backTop / anchor / tour 四个组件都是「挂 window 或容器的 scroll+resize 监听，从不摘」：单页应用里每次进页面重建组件就多一根监听，旧闭包连同旧 DOM 一起被 window 拽住，切十次页面就十份空转的 sync 在滚动时跑",
       "acceptance": "新增 watch.ts 的 watchViewport(root, host, handler)：滚动 / 缩放时若 root 已脱离文档就一次性摘掉两个监听并停止回调，否则转交 handler 并首帧同步一次；四个组件改用该助手，行为与原来一致（首帧同步保留）；npm run check 全绿",
       "notes": "自补：一致性与泄漏治理；一处实现四处复用，后续新增长期监听组件照抄",
-      "status": "open"
+      "status": "done"
     }
   ]
 }

.ua/iterations.log

@@ -150,3 +150,4 @@
 {"ts":"2026-10-26T13:54:09+08:00","id":"g103","result":"done","commit":"e497c16","summary":"dataTable 空状态分「暂无数据 / 没有符合关键词的行 + 一键清除筛选」，空状态行抽 tableEmpty.ts"}
 {"ts":"2026-10-26T13:55:22+08:00","id":"g104","result":"done","commit":"8e2175d","summary":"lint-iterations 回查留痕提交：哈希须真实存在且主题指向同一条目"}
 {"ts":"2026-10-26T13:56:59+08:00","id":"g105","result":"done","commit":"f398f09","summary":"tabs 支持 closable 页签（× / Delete 触发 onClose，指示条量外壳，触摸常显）"}
+{"ts":"2026-10-26T13:58:26+08:00","id":"g106","result":"done","commit":"c66bcf3","summary":"新增 watchViewport：affix/backTop/anchor/tour 的 scroll+resize 卸载后自摘，防空转累积"}