BOLT-1439 triage-wait watchdog: third 72h check; promote pattern if still Backlog/no-response

Follow-up from 2026-07-08 72h BOLT-1439 watchdog (second evidence comment). At lease: (1) query BOLT-1439 state + comments since 2026-07-08T04:55:52Z; (2) if state != Backlog OR any human comment since the watchdog comment, task event + complete; (3) if still Backlog with no response, empirically re-run the substrate check (fleet-tasks retry_count>=3, poison-pill, or lease-expired events since 2026-07-08T04:55Z), add ONE Linear comment on BOLT-1439 with evidence; (4) because this would be N=3 escalations with no response, promote the escalation-loop-detection pattern to AGENTS.md (or current durable guidance location) and DM Carson once with the BOLT-1204 -> BOLT-1439 arc summary. No repeated DMs beyond that single N=3 summary.