TODAY, FROM EARLY morning until late at night, it’s full of Brooklyn vegans in bucket hats and wire-rimmed glasses sporting microbangspeople with a stated preference for vinyl, oat milk, and natural wine. The 6,000-square-foot music venue and hangout spot Public Records, at 233 Butler Street in Gowanus, was once full of stray cats. For decades, it was home to the ASPCA, but, after a few intervening tenants, it has been transformed into a sort of postindustrial student union for postcollegiate human strays looking for a way to spend their days. It opens with coffee and Wi-Fi at 9 a.m. for impromptu co-working, and on the weekends, it keeps going till four in the morning with avant-garde music and $15 signature cocktails (Mezcal Melon, made with watermelon, Aperol, and Thai basil,…