An employee of a non-public protective device takes a swab pattern for a series of COVID-19 tests at a lockdown in Shanghai. SHANGHAI – Manufacturers, including Volkswagen Group and Tesla, began preparing on Monday to reopen their Shanghai plants, as China’s most populous city accelerates its efforts to return to normal after a nearly three-week COVID shutdown. Still, most of the staff will have to live there, and it’s unclear how factories will take care of disrupted supply lines and market access, with government-ordered closures in other cities and port and truck problems. The city’s closure and China’s pandemic measures…