delegate_task takes a task_id to hand over a task already on a list: it
moves to the worker (a workspace's task stays on its list), goes to
doing, and the job is linked back so its end is noted on the task.
hand_over_schedule moves a bot's own routine to another bot, keeping its
workspace. Users get Hand over in the Tasks UI and both routine lists.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
