BoyNextDoor uploaded a timetable for its promotional activities for its first studio recording, “Home,” via agency KOZ Entertainment on Monday. An assemblage of objects — from a key and a photograph to a postcard and a notebook — lists pending activities leading up to the release of the LP, due out June 8. The six-member act dropped a prerelease from the set, “Ddok Ddok Ddok,” Monday. The hip-hop tune refers to knocking sounds on the “door” in the group’s name. The single charted at No. 56 on Me