The fierce LGBTQ+ party Trade was the UK’s first legal after-hours club event, opening at 3am and closing at 9am. It laid the groundwork for a new on-and-on party culture, while its sexual and gender diversity was a forerunner for today’s queer club scene. As it celebrates its 30th anniversary, and prepares for its 24-hour birthday party at Egg London, Joe Roberts speaks to some of its regular DJs, designers and founder Laurence Malice about Trade's boundary-breaking legacy