A powerful artificial intelligence model that appeared anonymously on a developer platform last week was revealed on Wednesday to be from Chinese smartphone and EV giant Xiaomi, after it fueled speculation that startup DeepSeek was quietly testing its next-generation system ahead of a launch.The release of DeepSeek's low-cost models DeepSeek-V3 and R1 triggered a global tech stock selloff last year, causing investors to question whether U.S. AI firms needed to spend billions of dollars on AI computing power. Since then, there has been a great deal of interest in DeepSeek-V4, a next-generation model ?that has yet ?to be ?released.The mysterious…