HONG KONG—A Hong Kong court granted HK$10 million ($1.3 million) bail on Wednesday to media tycoon Jimmy Lai, the highest profile pro-democracy activist charged under the city’s new national security law on suspicion of colluding with foreign forces. An immediate appeal by the prosecution was then denied on the same day. Lai is one of the financial hub’s most ardent critics of Beijing, while his Next Media group is considered one of the key remaining bastions of media freedom. He was arrested in August when about 200 police officers raided the newsroom of his Apple Daily tabloid. Lai, 73, who had been in custody since Dec. 3, is also charged with fraud related to the lease of a building that houses Apple Daily. The security law—which punishes what Beijing broadly defines as secession, subversion, terrorism, and collusion with foreign forces with up to life in jail—has been condemned by the …