PORT-AU-PRINCE — More than two centuries after enslaved Africans gathered at Bois-Caïman in northern Haiti in a moment that became central to the story of the Haitian Revolution, the Haitian government has formally made Aug. 14 a national holiday. The decision gives official state recognition to a date long commemorated by Haitians, historians and scholars as a symbol of resistance, unity and the struggle for freedom. According to an Aug. 10 ann…