BEIJING — Infected patients quarantined alongside those who tested negative. No food for hours, despite repeated requests. Lines of buses, loaded with people, waiting late into the night to drop them off at makeshift isolation centers. These are the scenes described by residents of Lhasa, the capital of Tibet, who have been locked down for one month as officials try to contain a coronavirus outbreak. Lockdowns, including of entire cities, have become almost commonplace in China, which remains bent on eliminating the coronavirus even as the rest of the world…