Bash monitor timeout message now reports event count and distinguishes flush/bounded behaviour

When a background monitor watching a running bash command times out, Claude Code used to show a flat "[Monitor timed out — re-arm if needed.]" message. Now the message reports how much time passed and how many events the monitor actually delivered before it expired, or says plainly that no events were delivered. Monitors also gained a way to flush pending events and count how many have fired, plus a "bounded"/"quiet" mode that can flush accumulated output right before the timeout fires instead of just cutting off.