Chinese technology billionaire Chen Tianqiao’s artificial intelligence start-up MiroMind is suspending its services in mainland China, Hong Kong and Macau, in the latest sign that some of the country’s most globally ambitious firms are increasingly retreating from the domestic market as geopolitical tensions reshape the industry following the Manus saga. In an email sent to select users on Wednesday, the company said that its MiroThinker services would stop operating in regions including...