Kayvon Beykpour is one of Silicon Valley’s busiest product executives. As Twitter’s head of product, he’s survived for years in a formerly-cursed role that seemed to turn over every few months. Now, Beykpour’s team is shipping. Twitter just released a Clubhouse clone, called Spaces. It bought Revue, a newsletter platform. And it just announced Super Follow, a feature that wraps it all together by letting you pay for added access and content from people you follow on Twitter. This is new territory for Twitter, which spent the past few years