Dino of Seventeen will roll out his first solo EP, “Board,”on Aug. 3, his agency Pledis Entertainment announced Monday. But he will do so as Picheolin, his alter ego middle-age producer who runs a record label, a character the youngest member of the team first adopted for the group’s fan meeting in 2021. A seven-minute long teaser video in the form of a morning show — featuring him as multiple personas — took his fans by surprise, raising expectations for the upcoming set. The title itself hints