Kathy Wylde has left the Partnership for New York after a quarter-century. The group seems to be embarking on a new, more aggressive era ahead. Photo: Shuran Huang When Kathy Wylde stood onstage at her retirement party on a frigid Tuesday night in late January, looking out over the Rainbow Room and the glittering lights of the city below, she had a simple message for the masters of the universe who had come to see her off: Don’t panic. “We are going to do great going forward,” she told them,