Step 1Pick over the crab to remove any shell or cartilage. Place the crab in a bowl and add the chopped mint, cilantro, chives and enough mayonnaise to make the mixture cling together. Mix well. Season with one-fourth teaspoon salt and a pinch of pepper, or to taste.
Step 2Lay 1 spring roll wrapper out on a work surface, with one corner facing you. Spoon 2 heaping tablespoons of crab in a crosswise strip about 2 1/2 inches from the bottom corner. Roll the spring roll up like a burrito: fold over the sides to cover the filling, and roll up from the bottom. Brush the last corner with egg wash, and continue rolling the spring roll, sealing the last corner. (The rolls can be made to this point and refrigerated, tightly covered.)
Step 3For the dipping sauce, combine the lime juice, fish sauce, sugar, ramps and chile paste to taste in a bowl and whisk to dissolve the sugar. Set aside.
Step 4Pour peanut oil to a depth of about 2 inches into a wok or skillet and heat to 365 degrees. Working in batches, fry the spring rolls until crisp and evenly browned, about 2 minutes. Drain on paper towels.
Step 5Serve the spring rolls with lettuce leaves and herb sprigs to wrap around them before dipping in the sauce.