Preheat the oven to 350 degrees F. Spray 2 large rimmed baking sheets with cooking spray.
Cut the wonton wrappers in half and arrange them on the baking sheets in a single layer. Spray the tops with cooking spray. Bake until crisp and golden brown, 6 to 7 minutes.
Whisk the soy sauce, orange juice, lime juice, lemon juice, sesame oil, ginger, Fresno pepper and scallions together in a medium bowl. Add the tuna and toss to coat. Cover and refrigerate for at least 2 hours and up to 8 hours.
Before serving, add the radishes, cucumbers, avocado and the sesame seeds to the tuna and gently stir to combine; season with salt to taste. Transfer to a serving bowl with the wonton chips on the side.