Within two years of graduating from college, Cecilia A. Horan had already found her a dream job. It was at a Chicago area radio station where they played hard rock and heavy metal 24/7.Horan was the “on-air talent” — radio people do not call them DJs, she added — for the “Graveyard Shift” at Highland Park-based WVVX-FM 103.1, playing tracks that featured blazing guitar solos and thunderous double-bass beats from midnight to 5 a.m. She was also the production director, writing and …