BANGKOK (AP) — Chen Zhi boasted of pulling in $30 million a day, prosecutors in the United States said — a suspected criminal mastermind and onetime internet cafe manager who authorities say presented himself as a legitimate businessman. But in reality, they say, he ran online gambling sites, scams and other illegal businesses from a sprawling headquarters along the Cambodian coast. On Thursday, Chen was in custody in China, at the center of what authorities at the Chinese Ministry of Public Security said was a “major achievement” in law enforcement cooperation between them and the Cambodian government.