Short label shown in the spinner column (padded to 12 chars).
Descriptive message shown next to the label.
Whether the session is interactive (controls spinner vs plain log).
Async work to run; returns a PrefetchResult.
Width of the host's status-tag column, so a running row's label lines up with the finished row that replaces it.
Run a prefetch action behind a spinner (interactive) or plain log (non-interactive).