MARS-102 Weekly ux-pain digest delivery: move to Vercel-cron→authenticated-POST-to-hub→PM-drains-on-reconnect (remove relay-row/always-on-agent dependency). Blocked on llmmsg-maintainer answers: (1) can Vercel POST to hub from outside the reverse tunnel with an auth key, (2) unread-buffer retention/TTL must exceed weekly digest interval so an offline PM still receives it. Applies to mars (replace MARS-84 relay-row) + venus + pluto toast-ports. db agents are NOT 24/7 so a db-host cron is not viable; only nw agents + maybe PMs run 24/7.