Place potatoes in a microwavable dish. Microwave at high until potatoes are almost tender, about 2 minutes. Place bacon in a large skillet. Cook over medium-high until bacon begins brown, 5 to 6 minutes. Add shallot and potatoes to skillet; reduce heat to medium, and cook, stirring occasionally, until bacon is done and potatoes are soft and beginning to brown, 3 to 4 minutes. Transfer mixture to a bowl; cover to keep warm. (Do not wipe skillet clean.) Whisk together eggs, 2 tablespoons water, and salt in a medium bowl until well combined. Add egg mixture to skillet. Cook, stirring constantly, until eggs are almost set, 1 to 2 minutes. Stir together mayonnaise and Sriracha in a small bowl. Spread sauce evenly over tortillas. Layer potato mixture, scrambled eggs, and arugula evenly down center of tortillas; fold tortillas burrito-style. Serve immediately.