The "[queued — waiting for run X on the same host]" and run-slot lines were
broadcast to live viewers and never stored, so a run that sat queued had no
record of why once the live view was gone (CI 8439: the overlap test found
the order right and the explanation missing). _claim_hosts now returns the
line it waited on and start_run seeds the run's output with every wait.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>