"I love you," the widow of Alexei Navalny said in a post on social media beside a picture of them together, two days after President Vladimir Putin's most prominent domestic foe died in a Russian jail. Yulia Navalnaya's post on Instagram, the first since her husband died, showed a picture of the two together, their heads touching as they watched a performance. It brought a personal note to the loss she expressed more formally on a public stage just hours after her husband's death was announced by the Russian prison service. Navalny, 47, fell unconscious and died on Friday after a walk…