fix(schedules): anchor purge grace window to first cron fire

shared/schedule-policy.ts

@@ -62,7 +62,9 @@ export const SCHEDULE_POLICY = [
   { _tag: 'observed', taskName: 'detect-star-surges', cron: '30 4 * * *', maxSilenceSeconds: 36 * 60 * 60, maxRuntimeSeconds: 30 * 60 },
   { _tag: 'observed', taskName: 'drain-skill-dirty', cron: '*/5 * * * *', maxSilenceSeconds: 20 * 60, maxRuntimeSeconds: 4 * 60 },
   { _tag: 'observed', taskName: 'embedding-parity-audit', cron: '0 21 * * *', maxSilenceSeconds: 36 * 60 * 60, maxRuntimeSeconds: 30 * 60 },
-  { _tag: 'observed', taskName: 'purge-personal-data', cron: '30 4 * * *', maxSilenceSeconds: 36 * 60 * 60, maxRuntimeSeconds: 10 * 60, activeFromSeconds: 1789603200 },
+  // First cron fire, not the authoring date: a grace anchored to 2026-09-17
+  // expired before the deployed trigger ever fired and read as missing_run.
+  { _tag: 'observed', taskName: 'purge-personal-data', cron: '30 4 * * *', maxSilenceSeconds: 36 * 60 * 60, maxRuntimeSeconds: 10 * 60, activeFromSeconds: 1790051400 },
   { _tag: 'observed', taskName: 'recompute-skill-scores', cron: '0 3 * * *', maxSilenceSeconds: 36 * 60 * 60, maxRuntimeSeconds: 60 * 60 },
   { _tag: 'observed', taskName: 'refresh-x-engagement', cron: '10 * * * *', maxSilenceSeconds: 3 * 60 * 60, maxRuntimeSeconds: 30 * 60 },
   { _tag: 'observed', taskName: 'reconcile-rendered', cron: '20 */6 * * *', maxSilenceSeconds: 15 * 60 * 60, maxRuntimeSeconds: 30 * 60 },

test/unit/scheduled-run.test.ts

@@ -134,6 +134,23 @@ describe('scheduled run lifecycle', () => {
     )).toMatchObject({ _tag: 'missing_run', alertable: true })
   })
 
+  // purge-personal-data was authored 2026-09-17 but its first cron fire is
+  // 2026-09-22T04:30Z. An authoring-date anchor expired its 36-hour grace four
+  // days before that fire, so the nightly report raised a false missing_run.
+  it('keeps purge-personal-data healthy until its first cron fire passes', () => {
+    const policy = observedSchedulePolicy('purge-personal-data')
+    expect(policy.cron).toBe('30 4 * * *')
+    const firstFire = 1_790_051_400 // 2026-09-22T04:30Z
+
+    expect(evaluateScheduleHealth(policy, { latest: null, latestTerminal: null }, firstFire - 1))
+      .toMatchObject({ _tag: 'healthy', alertable: false })
+    expect(evaluateScheduleHealth(
+      policy,
+      { latest: null, latestTerminal: null },
+      firstFire + policy.maxSilenceSeconds + 1,
+    )).toMatchObject({ _tag: 'missing_run', alertable: true })
+  })
+
   it('observes the digest on its monthly schedule', () => {
     const policy = observedSchedulePolicy('send-digests')