WBAI likes to call itself “radio for the 99 percent.” But most of the time the station — a listener-supported and proudly scrappy mainstay of the left since 1960 — is lucky to be heard by 0.1 percent of the New York radio audience. That disparity, and the teetering finances of the station and its owner, the nonprofit Pacifica Foundation, became apparent with a tearful on-air announcement by Summer Reese, Pacifica’s interim executive director, that the station was laying off 19 of its 29 employees just to cover basic expenses like the rent for its transmitter atop the Empire State Building.