KAMPALA, Uganda— Pavel Prigozhin was still learning the family guns-for-hire business when his father’s private jet exploded 28,000 feet over Russia. Yevgeny Prigozhin’s very public death, following his very public falling-out with President Vladimir Putin, left his son, Pavel, in charge of the world’s most notorious mercenary force. At age 25, he inherited Wagner Group, an empire of gunfighters, gold smugglers, opioid dealers, brewers and vodka distillers. Once seen as a pampered playboy, he turned out to be a natural. Pavel Prigozhin, now 28, not only salvaged but expanded operations in Wagner’s African stronghold, the Central African Republic, according to…