Ejae is seizing her moment. Awards season has been very good to “Golden,” the song she sang lead on (and helped write) from “KPop Demon Hunters.” That makes it time to launch a solo career. “Time After Time,” written by Ejae and three others, is a peppy tune with a morbid undercurrent under its insistent hooks. The singer tearfully mourns “life without you” and is haunted by “your ghost.” But she’s attached beyond reincarnation: “Every lifetime I’ll be yours,” she sings. Is it a breakup song or a memorial?