The maker of Triscuit crackers sold in North America violated a collective bargaining agreement by barring employees from working seven days a week, a federal judge held.In a written opinion last week, U.S. District Judge Matthew F. Kennelly confirmed an arbitration award in favor of a union that represents employees at the Naperville bakery of Mondelez Global LLC.The union sought arbitration after Mondelez in June 2015 halted a longtime practice of letting employees work seven consecutive days.In August 2016, arbitrator …