Add a new field to the alert schema to fix a mismatch between the prior schema and the upstream NWS API

internal/sinks/postgres/map.go

@@ -302,6 +302,7 @@ func mapAlertEvent(e fkevent.Event) ([]fksinks.PostgresWrite, error) {
 				"sent":             nullableTime(a.Sent),
 				"effective":        nullableTime(a.Effective),
 				"onset":            nullableTime(a.Onset),
+				"ends":             nullableTime(a.Ends),
 				"expires":          nullableTime(a.Expires),
 				"area_description": nullableString(a.AreaDescription),
 				"sender_name":      nullableString(a.SenderName),