SAN DIEGO — Surging fan interest in the Padres, accelerated by trade-deadline moves that included the addition of 23-year-old superstar Juan Soto, is expected to cause the franchise to implement the first season-ticket-sales cap in history. CEO Erik Greupner told the San Diego Union-Tribune the club already has eclipsed the sales record of 18,808 established in 2004, the season Petco Park opened. New ticket requests for the 2023 season pushed that total to more than 20,200 since news of the Soto trade broke. “The fan response has been exceptional,” Greupner said. “Right now, people are realizi…