chore(backlog): 记录 g308 完成

.ua/backlog.json

@@ -3162,11 +3162,11 @@
     {
       "id": "g308",
       "domain": "tune",
-      "status": "open",
+      "status": "done",
       "title": "sortableList 支持拖到边缘自动滚，摘掉「长列表拖不动」的限制",
       "motivation": "文档里写明「拖到边缘不会自动滚动，条目超过一屏就别用」，这等于把最常见的场景（几十条检查单）挡在门外：拖到容器下沿不动，用户只能反复滚动重来。",
       "acceptance": "① dragstart 里一次算好最近的纵向滚动祖先（overflow-y auto/scroll 且确已溢出），dragover 每帧只在贴边 48px 感应带内按帧滚 12px；② 离开感应带或 dragend 立即取消帧并清状态，不留后台 rAF；③ 找不到滚动祖先（整页滚动）时不接管；④ manifest 步骤与配方 19 要点同步改写，npm run check 全绿。",
-      "notes": ""
+      "notes": "dragstart 用 scrollHost() 一次算最近纵向滚动祖先（overflow-y auto/scroll 且已溢出），dragover 在上下 48px 感应带内按帧滚 12px（EDGE_BAND/EDGE_STEP 常量），离开感应带或 dragend 取消 rAF 并清 scroller/edgeDir；找不到祖先不接管；manifest 步骤与配方 19 要点同步"
     }
   ]
 }

.ua/iterations.log

@@ -352,3 +352,4 @@
 {"ts":"2026-10-27T00:34:25+08:00","id":"g305","result":"done","commit":"08f14ce","summary":"新增 masonry 瀑布流（89 组件）：多列布局，列宽自适应或固定列数"}
 {"ts":"2026-10-27T00:35:35+08:00","id":"g306","result":"done","commit":"0ce51eb","summary":"audit:surface 增两档淡底可见度校验，暗色弱档降到 2% 即拦下"}
 {"ts":"2026-10-27T00:36:37+08:00","id":"g307","result":"done","commit":"6dfc2f8","summary":"新增 --ua-z-raised 且拖拽行用上，投影不再被后续行遮住"}
+{"ts":"2026-10-27T00:37:46+08:00","id":"g308","result":"done","commit":"f1916ef","summary":"sortableList 贴边自动滚：拖到容器上下沿按帧滚动，松手即停"}