Scheduled tasks that send messages via send_message (IPC) instead of
returning text as result left the container idle for ~30 minutes until
the hard timeout killed it (exit 137). This blocked new messages for
the group during that window.
Root cause: scheduleClose() was only called inside the
`if (streamedOutput.result)` branch. Tasks that communicate solely
through IPC (e.g. heartbeat check-ins) complete with result=null,
so the 10s close timer was never set.
Fix: also call scheduleClose() on status==='success', covering both
result-based and IPC-only task completions.
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>