Context

run_scheduler_loop() (modified in #1603) exits with GraphStatus::Failed when the channel is closed (Ok(None) or Err(_) from channel.recv()). This transition is not directly tested.

Acceptance criteria

A #[tokio::test] that:

1. Builds an agent with a MockChannel that immediately returns Ok(None) from recv()
2. Runs run_scheduler_loop() with an active graph
3. Asserts the returned status is GraphStatus::Failed

Note: MockChannel::new(vec![]) already returns Ok(None) when the message list is empty, so this test can be simple.

Labels

enhancement, testing