0.3.40

Agent teams were wired to the subagent execution engine but never actually ran a
member. Four defects compounded, each of them silent: the tools reported success
and the team produced nothing.

Requires subagents-pydantic-ai >= 0.2.12, which adds the programmatic
answer_task / steer_task surface and exposes SubAgentToolset.registry.

Fixed

• Teams registered members in a registry the subagent engine never reads. With
  subagent_registry=None — the create_deep_agent default — the team block built
  a fresh DynamicAgentRegistry(), so spawn_team put its members somewhere the
  subagent task tool does not look and every assign_task came back
  Error: Unknown subagent. Teams plus subagents was broken in the default
  configuration. Teams now share subagent_toolset.registry.
• A refused delegation was recorded as a started task. The subagent task tool
  reports an unknown subagent or a busy chat trace as an error string rather than
  raising, so assign_task's except never fired: it set the member to running
  and appended the error to an "Agent running in background" message. The member
  then sat at running forever. A started task is now identified by its Task ID:
  line, and a refusal marks the member failed with the reason.
• message_teammate delivered nothing. It wrote to TeamMessageBus, which no
  running member reads — a member is a background subagent and only sees what the
  subagent engine hands it, and TeamMessageBus.receive() is called from tests
  only. It now routes through the engine: answer_task when the member is blocked
  in ask_parent, steer_task while it runs, and it says plainly when there is
  nothing to deliver into instead of reporting "Message sent".
• A finished member left its shared task in_progress forever, so the lead read
  completed work as outstanding. AgentTeam.sync_member completes the todo when a
  member completes, and releases the claim when one fails so the lead can reassign
  it rather than watching a dead member hold it.

Added

• create_team_toolset(subagent_toolset=...) — the subagent toolset backing
  execution, which is what makes message_teammate able to deliver. The existing
  registry / task_fn / task_manager arguments still work.
• TeamMemberHandle.todo_id, linking a member to the shared-todo item it
  claimed so finishing the task can close the todo.
• TestTeamSubagentWiring in tests/test_teams.py, which fails on each of the
  four defects independently.

Changed

• TestCreateTeamToolset::test_message_teammate asserted the "Message sent" that
  the third defect shows was a lie; it now asserts the honest outcome.