delegate_task had no workspace argument: a task handed over from the
coordinator's own chat always ran in the worker's own chat, on that
worker's memory, files and directly assigned computers alone, even when
the work belonged to a workspace. The coordinator could not say where the
work goes, and the prompt never said the two differ.
- delegate_task takes an optional workspace_id: the worker runs the task
in that workspace's context, with its own instructions and memory
there, the project's files and the workspace's computers, and the
result lands in its conversation in that workspace.
- A worker missing from that workspace is added first (pushBotCreated)
and the reply says so.
- Handed over from inside a workspace the task always runs there; a
different workspace_id is refused instead of ignored.
- The coordinator prompt, CoordinatorReplyNote and the tool description
now spell the distinction out.