chore(backlog): 记录 g83 完成

.ua/backlog.json

@@ -1027,7 +1027,7 @@
       "motivation": "开关底层是 input type=checkbox，读屏一律播报成「复选框」，与视觉上的开关语义不符；不留 label 时更是完全没有可访问名（只有一个匿名复选框）",
       "acceptance": "input 补 role=switch（选中态沿用原生 checked 映射）；新增可选 ariaLabel，缺省取 label，纯图标开关也有可访问名；文档 props 与演示（无文案开关实例）同步；npm run check 全绿",
       "notes": "自补：无障碍；沿用原生 checkbox 的 Space 切换行为，不重造键盘交互",
-      "status": "open"
+      "status": "done"
     }
   ]
 }

.ua/iterations.log

@@ -127,3 +127,4 @@
 {"ts":"2026-10-26T12:58:08+08:00","id":"g80","result":"done","commit":"c324afc","summary":"通知自动关闭改为可暂停：悬停/聚焦扣减已流逝时间，离开按剩余续计"}
 {"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"}