The old City Hall subway station in lower Mangattan on April 10, 2019. The station, which has been out of commission since 1945, is famous for its arches. (Hiroko Masuike/The New York Times) By JEFFERY C. MAYS As hundreds of thousands of people amass in Times Square for the annual New Year’s Eve ball drop, a much smaller gathering of historical importance will begin underground at a long-abandoned subway station. Mayor-elect Zohran Mamdani will be sworn into office at the old City Hall subway...