fix: synchronize scheduled task status and run actions

Reflect queued and active schedule runs in task status, refresh tasks on queue changes, and prevent duplicate Run Now actions until the current run finishes. Add lifecycle regression coverage and update scheduled task behavior documentation.

This file-level commit also includes concurrent conversation history, browser workbar, and runtime selection changes in the affected files. Focused schedule regressions passed; full workspace validation has unrelated failures as recorded during development.

Release note: Scheduled tasks now refresh their queued and running status and keep Run Now disabled while an occurrence is active.

docs/features/task-and-job/scheduled-task-prd.md

@@ -225,7 +225,10 @@ type TimeTrigger =
 ### 7.3 手动触发
 
 “立即运行”在当前 Task 内创建独立 Job 和 Run，不改变下一次计划时间，不创建新 Task。
-重复点击使用调用级幂等键去重。
+提交期间，以及该计划已有排队或运行中的 occurrence 时，“立即运行”不可重复点击。
+后台同样拒绝为已有活动 occurrence 的计划再次入队。
+任务状态随队列变化刷新：待执行显示 queued，认领执行后显示 running；结束或取消排队后
+重新读取当前状态。没有活动 occurrence 的周期计划显示 idle 或 paused。
 
 ### 7.4 与普通消息的顺序