Smoky Sheet Pan Clambake

Name: Smoky Sheet Pan Clambake
Ingredients: 2 pounds multicolored baby creamer potatoes; 2 tablespoons olive oil; 1 teaspoon kosher salt, divided; 1 pound hot Italian sausage, casings removed; 6 tablespoons unsalted butter, melted; 1 teaspoon smoked paprika; 1 teaspoon celery seeds; 1 pound peeled and deveined tail-on extra-large shrimp; 2 pounds mussels, scrubbed and debearded; 3 pounds littleneck clams, scrubbed; Chopped fresh flat-leaf parsley leaves, for serving; Lemon wedges, for serving