Background worker that detects stale messages and takes corrective action:
- Auto-fails DMs stuck in "processing" after configurable timeout (default 24h)
- Sends system DM reminders for pending messages after ReminderAfter (default 4h)
- Escalates unprocessed messages to #approvals channel after EscalateAfter (default 48h)
- Deduplicates reminders and escalations to avoid spam
- Configurable via SYNAPBUS_STALEMATE_* environment variables
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>