NEW YORK — The hopes and dreams of a young Metropolitan Opera stagehand disappeared in an instant beneath a No. 1 train. The family of Joseph Ancona, dragged to his death after running to board an uptown Manhattan subway car following his Monday shift, was remembered as a vibrant young man with an ever-present grin, a love of sports and a girlfriend of four years. “He was like the happiest-go-lucky,” his uncle Dan Coli told the Daily News on Wednesday. “They called him ‘Smiles,’ ’cause he always smiled and he was always laughing. … He was just a sweet kid.” Ancona, 20, grew up in the north J…