By Eduardo Baptista and Andrew Galbraith BEIJING/SHANGHAI (Reuters) -Beijing residents tentatively returned to work on Thursday after a muted five-day Labour Day holiday devoid of the usual trips across the country or lavish family dinners, as China pledged to fight any criticism of its uncompromising “zero-COVID” policy. The long break is usually one of the most lucrative times of the year for restaurants, hotels and other businesses in China. This year, travellers spent 43% less than in 2021, data showed on Thursday. It was the latest sign of the pain caused by COVID curbs imposed on dozens of major population...