ATLANTA — The Atlanta Braves and shortstop Andrelton Simmons agreed on a $58 million, seven-year contract on Thursday, a record deal for the latest young star locked up by the NL East champions. The deal, which runs through the 2020 season, is the largest ever awarded to a player subject to American draft rules with less than two years of service time. Cubs first baseman Anthony Rizzo signed a $41 million, seven-year contract last May.