CHICAGO — Mayor Brandon Johnson’s administration fired three city staffers after they complained about how they were treated by high-ranking officials, records show. The episode unfolded early in the administration, and its fallout continued into the autumn. It offers a window into the bumpy transition in the mayor’s office from Lori Lightfoot to Johnson. Two days after Johnson was inaugurated in May, top City Hall adviser Jason Lee walked into a press aide’s office and began yelling, according to a complaint filed by former deputy director of digital strategy Dora Meza with the state’s human …