Chinese e-commerce giant JD.com has opened a new front in China’s intensifying on-demand local services war, rolling out a stand-alone food-delivery app and a “JD Review” platform for what it says are genuine, non-commercialised user ratings, in a direct challenge to Meituan and Alibaba Group Holding-backed services. The twin launches mark JD.com’s latest attempt to claw back relevance in instant commerce, a fast-growing segment where Meituan and Alibaba have consolidated dominant positions,...