点击「转后台」后立刻 reset 回初始页,挂起请求 fire-and-forget; 历史下拉靠 markBackground/clearBackground 乐观标记马上显示「挂起中」, 不等后端确认,与「多智能体会商」交互一致。 Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>