feat: add persisted page insight platform

internal/eventcatalog/catalog.go

@@ -104,6 +104,18 @@ func ValidateEvents(events []Event) error {
 		if event.LeadDays < 0 || event.LagDays < 0 || event.RelevanceBPS < 0 || event.RelevanceBPS > 10_000 || event.ConfidenceBPS < 0 || event.ConfidenceBPS > 10_000 {
 			return fmt.Errorf("event catalog: event %q has invalid impact metadata", event.ID)
 		}
+		if event.LeadDays > 90 || event.LagDays > 90 {
+			return fmt.Errorf("event catalog: event %q lead or lag window exceeds 90 days", event.ID)
+		}
+		if event.Recurrence != "" {
+			resolved, err := ResolveRecurrence(event.Recurrence, start.Year(), time.UTC)
+			if err != nil {
+				return fmt.Errorf("event catalog: event %q recurrence: %w", event.ID, err)
+			}
+			if !resolved.Equal(start) || !end.Equal(start) {
+				return fmt.Errorf("event catalog: event %q does not match its resolved recurrence", event.ID)
+			}
+		}
 	}
 	return nil
 }