The Cookbook download path showed its error toasts with the default ~1.2s
duration, so an actionable message like "tmux is required for Cookbook
background downloads/serves … install it with your OS package manager" vanished
before it could be read (issue #1355). The serve path already uses multi-second
durations.
Give the three "Download failed" toasts a 9s duration to match.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
