San Diego Repertory Theatre is giving “In the Time of the Butterflies,” the story of four sisters’ valiant fight against Dominican Republic strongman Rafael Trujillo’s bloody regime, its English-language world premiere through Jan. 26. Curiously, the entry is missing a lot about its flesh-and-blood antagonist — but a highly developed culture of ensemble carries the performances in this commendable piece about a brutal reign the West can’t afford to forget.