Daily life in Shanghai has ground to a halt as parts of the city’s social services collapsed under the weight of a strict citywide Covid-19 lockdown that is stretching into a second month. Now, ordinary citizens have stepped up to fill the breach. Volunteers, some of them engineers and programmers at China’s biggest technology firms, have built an array of databases and networks to help provide disaster relief and information on medical care, pet shelters, how to cook with limited ingredients and other essential information. That is helping keep the city of 25 million afloat as some hospitals and public transportation are […]