chore(backlog): 记录 g84 完成

.ua/backlog.json

@@ -1035,7 +1035,7 @@
       "motivation": "列宽只能在定义时写死，长内容把列撑开就再也调不回去；表格库缺这个基本操作，用户只能改代码重发版",
       "acceptance": "width 为数字的列在表头右缘出现手柄：拖动实时改对应 <col> 宽度（下限 56px，拖出表头仍跟手），聚焦手柄后 ← → 每次 ±8px，双击复位到声明宽度；拖拽/双击不触发排序；拖拽期间全局禁选文本；样式走令牌且有 reduced-motion 兜底；dataTable ≤ 200 行；npm run check 全绿",
       "notes": "自补：可用性；拖拽与键盘共用 apply 单一写宽入口，逻辑拆到 columnResize.ts 免撑大 dataTable",
-      "status": "open"
+      "status": "done"
     }
   ]
 }

.ua/iterations.log

@@ -128,3 +128,4 @@
 {"ts":"2026-10-26T12:58:56+08:00","id":"g81","result":"done","commit":"f3c83e9","summary":"树改 roving tabindex：整棵树一个 Tab 停点，focusin 跟随焦点，keydown 复用 keyOf"}
 {"ts":"2026-10-26T13:00:21+08:00","id":"g82","result":"done","commit":"37412b3","summary":"upload 新增 maxSize/maxCount，accept 对拖拽生效，拒收原因走 role=status 提示行"}
 {"ts":"2026-10-26T13:01:16+08:00","id":"g83","result":"done","commit":"151b542","summary":"开关 input 补 role=switch，新增 ariaLabel 兜底可访问名，演示加无文案实例"}
+{"ts":"2026-10-26T13:02:41+08:00","id":"g84","result":"done","commit":"db5d38c","summary":"新增 columnResize 手柄：拖动/方向键改列宽、双击复位，定宽表头挂载"}