Duval’s School Board split down the middle on a vote Tuesday night, barely approving Superintendent Nikolai Vitti’s newest literacy plan.One of three board members voting against it, Constance Hall, said she couldn’t approve it because she was “heartbroken” and losing sleep over a lack of progress in closing achievement gaps. She said black and Hispanic students remain far behind their white and Asian peers, especially in reading. “We’re in the emergency room and we need help,” she said.