BEIJING—Residents of Shanghai are struggling to get meat, rice, and other food supplies under anti-coronavirus controls that confine most of its 25 million people in their homes, fueling frustration as the authorities try to contain a spreading outbreak. Zhang Yu, 33, said her household of eight eats three meals a day but has cut back to noodles for lunch. They received no supplies from the authorities. “It’s not easy to keep this up,” said Zhang, who starts shopping online at 7 a.m. “We read on the news there is (food), but we just can’t buy it,” she said. “As soon as you go to the grocery shopping app, it says today’s orders are filled.” The complaints are an embarrassment for the Chinese Communist Party (CCP) during a politically sensitive year when its leader Xi Jinping is expected to try to break with tradition and award himself a third five-year term …