A love story like Ana and Lucas Altman’s could only happen in New York City.  The pair didn’t meet through rounds of speed dating, an awkward blind date or a lucky swipe on the apps. For the Altmans, Cupid came in the form of their doorman. Ana and Lucas met in 2011 as neighbors at 11 W. 69th St., a prewar co-op along a tree-lined block off Central Park West. Lucas, a television director for Major League Baseball, had just bought his first apartment, unit 1B. Ana was one of the first residents