Shrimp Scampi Meatballs in Garlicky Broth

Name: Shrimp Scampi Meatballs in Garlicky Broth
Ingredients: Coarse salt; 1/2 pound spaghetti; 3/4 pound shrimp, peeled and deveined, roughly chopped; 1/2 cup plain dried breadcrumbs; 1/4 teaspoon red-pepper flakes; 1/2 cup whole milk; 2 teaspoons grated lemon zest, divided, plus wedges for serving; 1/4 pound ground white-meat chicken; 3 tablespoons unsalted butter; 4 cloves garlic, thinly sliced; 4 cups chicken broth; 1/4 cup finely chopped fresh parsley