A new front has opened in China’s electric-vehicle tech war as carmakers design their own smart-driving chips, turning custom silicon into the industry’s weapon of choice in the world’s largest auto market.The latest salvo came on Monday after Li Auto unveiled the Mach M100, a 5-nanometre artificial-intelligence chip tailored for autonomous driving.Designed for the carmaker’s new L9 Livis SUV model, the chip displayed single-unit computing power of 1,280 trillion operations per second (TOPS) –...