Hong Kong prosecutors have cited an expert’s report on social media platforms in media mogul Jimmy Lai’s closely-watched national security trial, in which he stands accused of conspiring to collude with foreign forces and publishing “seditious” materials. Lai, the founder of the now-defunct Apple Daily newspaper, appeared before a panel of three handpicked national security judges on Tuesday as the trial entered its eighth day. Wearing a brown jacket, the 76-year-old smiled and made gestures at people in the public gallery while waiting for the proceedings to begin. Much of Tuesday’s court ses…