For decades, Hong Kong’s internet operated outside the reach of China’s vast army of censors, guaranteeing the free flow of information that undergirds the city’s status as a global business hub. Little by little, that is starting to change, as a small but growing list of websites go dark under a sweeping crackdown on dissent. The creeping censorship casts uncertainty over the future of the city’s free and open internet, a draw for international businesses that has remained largely untrammelled by a Beijing-imposed national security law (NSL) used to wipe out practically all political opposition and silence critical media and…