feat(payment): configure named gateway providers

packages/payment/src/index.ts

@@ -3,5 +3,6 @@ export * from "./store.ts";
 export * from "./database.ts";
 export * from "./core.ts";
 export * from "./adapters.ts";
+export * from "./config.ts";
 export * from "./contract.ts";
 export { paymentPlugin } from "./plugin.ts";