chore(backlog): 记录 g99 完成

.ua/backlog.json

@@ -1155,7 +1155,7 @@
       "motivation": "spinner 的 aria-label 写死「加载中」，页面里同时有三处加载时读屏念三次一样的话，用户不知道在等什么；组件没有出口让调用方说明加载对象",
       "acceptance": "SpinnerProps 新增可选 label，缺省仍是「加载中」（不传即旧行为）；role=status 保持不变；文档参数与手把手步骤、演示（带 label 的实例）同步；npm run check 全绿",
       "notes": "自补：无障碍；纯透传一个可选参数，行为向后兼容",
-      "status": "open"
+      "status": "done"
     }
   ]
 }

.ua/iterations.log

@@ -143,3 +143,4 @@
 {"ts":"2026-10-26T13:15:00+08:00","id":"g96","result":"done","commit":"306fd90","summary":"drawer placement 扩到四向，上下滑出按高度、横向铺满，复用焦点陷阱与 Esc 栈"}
 {"ts":"2026-10-26T13:15:34+08:00","id":"g97","result":"done","commit":"3fe1fe3","summary":"重新生成 CHANGELOG（267 提交），收尾确认与提交史一致"}
 {"ts":"2026-10-26T13:16:32+08:00","id":"g98","result":"done","commit":"c32f20c","summary":"modal/drawer 新增 closeOnOverlay，false 时点遮罩不关，× 与 Esc 不变"}
+{"ts":"2026-10-26T13:17:13+08:00","id":"g99","result":"done","commit":"a5d4faf","summary":"spinner 新增 label 可访问名，缺省仍为加载中"}