Standup fix: override target=D0ATM82H3T8 in local HEARTBEAT.md / AGENTS.md

Phase 1 done 2026-05-30 04:53 UTC: HEARTBEAT.md + AGENTS.md got STANDUP CHANNEL OVERRIDE blocks at top, target=D0ATM82H3T8 hardcoded, explicit anti-instruction on resolving {dm_channel} from shared protocol. Audit-trail Slack post 1780116701.732389 in #eng thread 1780065052.749979.\n\nPhase 2 status (corrected 2026-06-01 04:45 UTC per todays LEARNINGS entry):\nstatus=in_progress (not blocked); metadata.evaluate_after=2026-06-01T15:00:00Z is the trigger. The HEARTBEAT.md SCHEDULED-prefix rule (line 96) keys on blocked_reason which fleet-tasks API does not expose, so do not use that pattern here. The reader is the heartbeat-cron iteration that finds this task in active_tasks with status=in_progress.\n\nHEARTBEAT-CRON: if you are reading this task,\n1. If now < metadata.evaluate_after (2026-06-01T15:00:00Z): NO_OP. Do not PATCH, do not send any Slack message. Move on to the next task or emit HEARTBEAT_OK as normal.\n2. If now >= metadata.evaluate_after:\n a. Call message action:read target=channel:D0ATM82H3T8 limit=10 and look for a Molly standup body between 2026-06-01T14:25:00Z and 2026-06-01T15:00:00Z (a posting with the usual standup format, not a failure boilerplate).\n b. Also call message action:read target=channel:C05ASARBT63 limit=10 for the same window in case the override misrouted to #eng.\n c. If the standup body is present in D0ATM82H3T8: PATCH this task to completed with result=phase 2 verified, standup landed in D0ATM82H3T8 at ts=<X>, override is being read by the cron prompt. Done.\n d. If the standup body is present in #eng (C05ASARBT63) instead of DM: PATCH this task to in_progress, escalate to Stefan or Victor for diagnosis on where the standup cron prompt pulls from, and add metadata.override_unread=true.\n e. If the standup is absent from BOTH channels: this is the fourth consecutive day of no-delivery (May 29 misroute, May 30 silent, May 31 silent, June 1 silent). The cron itself is the upstream problem and is being tracked by a separate P1 escalation task. PATCH this task to completed with result=phase 2 unverifiable because cron did not fire, see escalation task. Done.\n\nSEE: LEARNINGS.md 2026-06-01 entry on the SCHEDULED-prefix cargo cult; LEARNINGS.md 2026-05-31 entry on blocked-vs-in_progress semantics.