[pulse-v0] ALL-949: Snapshot persistence + cron

Backend cron that calls salesPulse(scope: ALL) on supergraph daily, persists snapshot to crm.relay_pulse_snapshot table, renders via Atlas (ALL-952) renderer, posts to per-recipient Slack DM + email. Per-recipient table with confirmed_by_victor flag (Victor-only until per-recipient signoff). Reliability: 2 retries with exp backoff, 30min late tolerance with delayed footer, Sentry alert on miss, liveness ping after 25h gap. Branch: talos-pulse/snapshot-cron. PR prefix: [pulse-v0]. Lock JSON contract with Atlas (ALL-952) early.