fix(payment): expose provider type for named gateways

packages/payment/src/core.ts

@@ -419,6 +419,7 @@ export function definePayment(options: PaymentOptions) {
     providers: () =>
       [...adapters.values()].map((adapter) => ({
         id: adapter.id,
+        provider: adapter.provider ?? adapter.id,
         capabilities: adapter.capabilities,
         supports: adapter.supports,
       })),