MANILA, Philippines—Newly retired boxing star Manny Pacquiao filed his certificate of candidacy for the Philippine presidency Friday as registration opened for candidates seeking to lead a Southeast Asian nation that has been hit hard by the pandemic and deep political conflicts. Elections officials placed heavy restrictions to prevent the Oct. 1–8 registration period from drawing huge crowds of political supporters and becoming hotbeds for COVID-19 infections. Aside from the presidency and vice presidency, more than 18,000 national, local, and congressional posts will be contested in the elections on May 9, 2022. Considered an Asian bastion of democracy, the Philippines has also seen electoral mayhem and violence. In 2009, gunmen deployed by the family of Maguindanao province’s then-governor massacred 58 people, including journalists, in an attack on an election convoy that shocked the world. About 3,000 police officers, including some patrolling in armored police vans, were deployed around the seaside convention …