KUALA LUMPUR, Malaysia — The first comprehensive report into the disappearance of Malaysia Airlines Flight MH370 revealed Sunday that the battery of the locator beacon for the plane’s data recorder had expired more than a year before the jet vanished on March 8, 2014. Families of the 239 people who were on board the plane marked the anniversary of the Boeing 777’s disappearance Sunday, vowing to never give up on the search for wreckage and answers to what happened to their loved ones. The significance of the expired battery in the beacon of the plane’s flight data recorder was not immediately apparent, except indicating that searchers would have had lesser chance of locating the aircraft in the Indian Ocean, where it is believed to have crashed, even if they were in its vicinity. The 584-page report by a 19-member independent investigation group went into minute details about the crew’s lives, including their medical and financial records and training.