HAVANA — Cuba’s capital remained largely paralyzed on Monday and the rest of the island braced for the fourth night of a massive blackout that has generated a handful of small protests and a stern government warning that any unrest will be punished. Hurricane Oscar made landfall Sunday before crossing the island’s eastern coast as a tropical storm Monday with winds and heavy rain, leaving at least 6 dead after a night that saw protests by several dozen people in urban neighborhoods like Santos Suárez and central Havana. Some banged pots and pans in the streets, while others demonstrated from