When OpenAI’s board of directors ousted Sam Altman as CEO last year, it looked like a shocking derailment of a fast-rising career. Even after Altman returned to the role just days later, it seemed like he would be kept on a shorter leash. Instead, he has become more powerful than ever.His primary foes within OpenAI resigned or were pushed out. He is propelling the company’s board to overhaul OpenAI’s nonprofit structure so that it won’t conflict with the multibillion-dollar revenue business it i...