Avocado and Cucumber Salad

Name: Avocado and Cucumber Salad
Ingredients: 1 English cucumber , cut into ½-inch pieces (3 cups); ½ teaspoon table salt for salting cucumber; 2 tablespoons Kewpie mayonnaise; 2 teaspoons sriracha; ½ teaspoon plus 2 tablespoons unseasoned rice vinegar , divided; 3 scallions , sliced thin on bias; 1 tablespoon pickled ginger , minced; 1 tablespoon vegetable oil; 1 tablespoon soy sauce; 2 teaspoons sesame seeds , toasted; ½ teaspoon toasted sesame oil; 2 ripe avocados , quartered, pitted, and cut into ½-inch pieces; 1/2 cup crumbled roasted seaweed snacks , plus extra sheets for serving