From fiery foliage to summer swimming holes, these New York destinations deliver year-round.Aerial view of Main Street in Cooperstown, New York.Credit: Kyle Stephens/Getty ImagesThe Catskills have long been a retreat—first for 19th-century painters and writers, later for city escapees chasing mountain air and summer swims. That legacy hasn’t faded, but the region feels freshly alive these days as chefs, artists, and creative entrepreneurs put do…