Huaqiangbei, home to the world’s largest electronics marketplace in southern China’s tech hub Shenzhen, is reinventing itself as the world’s artificial intelligence showroom, drawing back foreign traders and tourists hunting for the latest gadgets. For first-time visitors like Abigail Slagveer from Rotterdam, the Netherlands, the sheer scale of Huaqiangbei’s electronics market is overwhelming. “I came here one and a half hours ago through that front door,” she said, pointing to an entrance just...