ATHENS—Greece will require customers at indoor restaurants, bars, and cafes to prove they have been vaccinated against COVID-19 or have tested negative within the last three days, the government announced on Tuesday to combat an infection surge. Under the new regulations, which will remain in force until August, all customers at indoor bars and restaurants will have to be seated. Those dining outdoors will not require proof of vaccination or a test. “It is crucial not to give the impression that we are losing control of the pandemic so that our tourism industry can go on and operate normally,” Development Minister Adonis Georgiadis told a news conference. “The course of Greece’s economy will hinge on how well we comply with the measures and control the pandemic.” A government-launched application, COVID FREE GR, which can scan European digital vaccination certificates or the results of PCR or rapid tests, will be available …