For one day at least, Russia’s opposition came alive to mourn its lost leader. The funeral of Alexei Navalny on Friday almost did not happen at all. But thousands ultimately turned out — braving the snow, heavy security and weeks of Kremlin efforts to derail the event — so that they could pay their respects to the man who challenged President Vladimir Putin with a vision for a democratic Russia. Bearing flowers, candles and placards, the crowd chanted Navalny’s name as his body was first delivered to a church in southern Moscow for a brief funeral and then to a...