Write & POST June 15 standup to Slack (12:30-13:30 UTC window) — queue-for-N+2 substrate fix

Routine daily standup. Posting window 2026-06-15 12:30-13:30 UTC. Mandatory step (0): isolated-statement token refresh (eval $(~/bin/gh-fleet-token.sh) on its own line, then verify GH_TOKEN length=40 on the next line). Send-side window guard: do NOT post before 2026-06-15T12:30:00Z. Dedupe gate: read last 25 Carson DMs to confirm no duplicate same-topic ping. Mandatory final-refresh: live gh pr view on #12218 (BOLT-1267 event-curve preview) + recovery cohort (#11428/#11429/#11440/#11517/#11569); check resume endpoint for new Carson asks; check #12218 fleet-task (retro-POSTed 2026-06-14 cron) for any review/CI events. Body composed dynamically at lease time. Atomic completion: PATCH this task to completed with metadata.slack_ts + memory_file + delivered_at immediately after Slack send succeeds.