At 3:30 p.m. today, a private attorney stepped in front of a bank of microphones in his downtown Baltimore office and told the city that the mayor had resigned. Catherine Pugh wasn’t there. She hasn’t been seen or heard from in public in weeks. Bernard C. “Jack” Young, the former City Council president who is now mayor, wasn’t either. He’s in Detroit at a conference. Andre Davis, the city solicitor who reportedly drafted the resignation letter that Ms. Pugh signed, wasn’t either.