Mail deliverability dashboard: findings with fixes, DMARC report ingestion, alerts on regressions

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

db.go

@@ -53,7 +53,7 @@ CREATE TABLE IF NOT EXISTS alert_events (
 	key TEXT, status TEXT, name TEXT, message TEXT
 );
 CREATE INDEX IF NOT EXISTS alert_events_org ON alert_events (org_id, id);
-`
+` + dmarcSchema
 
 type DB struct {
 	sql *sql.DB
@@ -547,6 +547,7 @@ func (d *DB) queryAudit(org string, limit int, before int64) []AuditEntry {
 
 // purge deletes logs older than the retention periods.
 func (d *DB) purge(accessDays, auditDays int) {
+	d.purgeDMARC(time.Now().AddDate(0, 0, -dmarcKeepDays))
 	if accessDays > 0 {
 		d.sql.Exec(`DELETE FROM access_log WHERE ts < ?`, ms(time.Now().AddDate(0, 0, -accessDays)))
 	}