Shrimp and Chicken Summer Rolls

In a small microwavable bowl, combine the sugar and water and microwave on high power just until the sugar is dissolved. Let cool, then stir in the remaining ingredients. Let stand for 30 minutes. Fill a medium bowl with ice water. In a medium saucepan of boiling salted water, cook the shrimp until pink, 2 minutes. Using a slotted spoon, transfer the shrimp to the ice water to cool. Peel and devein the shrimp, then pat dry and halve them lengthwise. Return the cooking water to a boil. Add the soaked rice vermicelli and cook until tender, about 2 minutes. Drain and rinse under cool running water. Drain again and pat dry with paper towels. Using scissors, cut the noodles into 2-inch lengths. Fill a bowl with hot water. Add 3 rice-paper wrappers, 1 at a time, and let soak until slightly softened but still a bit stiff, about 30 seconds; transfer to a work surface. Rub each wrapper with a little water until completely pliable, then blot dry with paper towels. Place 1 lettuce leaf on the lower third of each wrapper. Brush with a little of the hoisin and top with 3 shrimp halves, a scant 3 tablespoons of the shredded chicken and 3 mint leaves. Fold up the bottom edge of the wrapper, then fold the ends in and roll over once. Place a chive on the wrapper and continue to roll into a tight cylinder. Place the finished rolls on a large platter and cover with lightly moistened paper towels while you soak, fill and roll the remaining wrappers. Cut each roll in half diagonally and serve with the dipping sauce.