Crm Scheduler Health

Return CRM scheduler running flag + queue counts.

Output shape: { "is_running": bool, "last_tick_at": ISO8601 | null, "queue": { "pending": int, # status='pending' (any next_run_at) "due_now": int, # status='pending' AND next_run_at <= now "failed": int, # status='failed' — needs manual intervention }, "now": ISO8601 }