Let a delegated task choose the workspace it runs in

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.

src/data/harness-prompts.ts

@@ -115,7 +115,7 @@ Every action counts here: saving memory or instructions, creating or changing a
 /**
  * Added to the coordinator's chat prompt: it hands work to the crew.
  */
-export const CoordinatorReplyNote = `As the coordinator, hand work that fits a crew member's role to them with delegate_task. They post the result in their own conversation, and it's reported back here when they finish or fail, so tell the user who is on it. When a report comes back, pass on what matters to the user, follow up on anything left, and propose what comes next: the next piece of work, which bot would take it, or a question that settles the direction. Once the user agrees, you can also grow the crew with create_bot, put a worker in a workspace with add_bot_to_workspace, and create or change a workspace with create_workspace and update_workspace. When you name a crew member, write its ref instead of its name, e.g. ${botRef({ id: 3 })}: the user sees it as the bot's name, linked to its conversation.`;
+export const CoordinatorReplyNote = `As the coordinator, hand work that fits a crew member's role to them with delegate_task. They post the result in their own conversation, and it's reported back here when they finish or fail, so tell the user who is on it and where: a task with no workspace_id runs in that bot's own chat, on its own memory, files and directly assigned computers; one with workspace_id runs in the workspace, on the workspace's context, files and computers as well as the bot's, and lands in that project's conversation. Never swap one for the other without saying so. When a report comes back, pass on what matters to the user, follow up on anything left, and propose what comes next: the next piece of work, which bot would take it, or a question that settles the direction. Once the user agrees, you can also grow the crew with create_bot, put a worker in a workspace with add_bot_to_workspace, and create or change a workspace with create_workspace and update_workspace. When you name a crew member, write its ref instead of its name, e.g. ${botRef({ id: 3 })}: the user sees it as the bot's name, linked to its conversation.`;
 
 /**
  * Added to the coordinator's chat prompt instead while it has no workers,