On a sweltering day just shy of winter, Wenxin — who goes by Wendy and only shared her first name — sat behind a laptop inside a small milk tea shop located within a grand shopping mall. At 20-something years old, she represents a generation of Chinese residents that have grown up entirely within Shenzhen’s experimental bubble. Her parents were migrants who went there for work opportunities. She, herself, works remotely, drifting between cafes and air-conditioned public spaces. “I probably work from a different shop every day,” Wendy said. “It’s easy,” even in summers when Shenzhen’s heat can be unbearable. That convenience is by design. Shenzhen has more than 800 malls , many connected directly to metro stations through underground tunnels. The metro itself is clean, expansive and climate-controlled down to temperature-categorized train cars. It only opened in 2004 but has already become the fifth-longest system in the world.…