More than a decade into Xi Jinping’s rule, China’s military has grown more formidable, its factories dominate global manufacturing and its technology pioneers are closing the gap with Silicon Valley.  Yet big parts of its economy are a mess. A colossal property bust has destroyed trillions of dollars in wealth, consumer confidence has been gutted and the job market has grown bleak. The disconnect shows how Xi has made China’s security a priority over its economy. He is steering hundreds of billions of dollars into pursuing self-sufficiency in artificial intelligence, semiconductors, electric cars and other strategic sectors, while holding back…