chore(backlog): 记录 g131 完成

.ua/backlog.json

@@ -1410,7 +1410,7 @@
       "title": "新增悬浮操作按钮 floatButton",
       "motivation": "backTop 只能回顶，页面里「新建 / 帮助 / 客服」这类常驻悬浮入口没有统一件，各处自己 fixed 定位",
       "acceptance": "floatButton 固定右下角，支持 icon/label/tooltip/badge/点击回调与 position 偏移，键盘可达；样式只消费 --ua-*；文档与演示同步；npm run check 全绿",
-      "status": "open",
+      "status": "done",
       "notes": "自补：组件补充方向"
     },
     {

.ua/iterations.log

@@ -175,3 +175,4 @@
 {"ts":"2026-10-26T14:52:25+08:00","id":"g128","result":"done","commit":"b399640","summary":"收尾刷新 CHANGELOG（329 提交），顺带提交 g127 漏带的 llms-full.txt"}
 {"ts":"2026-10-26T15:18:37+08:00","id":"g129","result":"done","commit":"ea2a846","summary":"新增 typography 排版文本组件（标题 h1-h5/段落/行内 + 语义色/装饰位/对齐 + 多行截断 + 复制按钮），组件 60→61"}
 {"ts":"2026-10-26T15:20:05+08:00","id":"g130","result":"done","commit":"23d1e06","summary":"新增 grid 栅格容器（columns 固定列 / min auto-fit 自适应 / gutter / align / dense，窄屏单列），组件 61→62"}
+{"ts":"2026-10-26T15:21:23+08:00","id":"g131","result":"done","commit":"d9559ae","summary":"新增 floatButton（左下/右下停靠、label 胶囊与纯图标圆形、badge 角标、tooltip 兼 aria-label、reduced-motion 兜底），组件 62→63"}