refactor: ( payment ) use rabbitmq for webhooks event

apps/edr-payment-api/src/config/rabbitmq.config.ts

@@ -0,0 +1,23 @@
+import { registerAs } from "@nestjs/config";
+
+/**
+ * RabbitMQ connection for the outbox event publisher (payment -> apps).
+ * `publisherTransport` selects which PaymentEventPublisher the outbox relay uses:
+ *   "rabbitmq" -> RabbitMqPaymentEventPublisher (publish to the payment.events exchange) [DEFAULT]
+ *   "http"     -> HttpPaymentEventPublisher (POST to each app's mark-paid endpoint) [rollback]
+ * RabbitMQ is the default; set PUBLISHER_TRANSPORT=http explicitly to fall back to HTTP.
+ */
+export default registerAs("rabbitmq", () => ({
+  url: process.env.PAYMENT_RABBITMQ_URL ?? "amqp://localhost:5672/payment",
+  publisherTransport: (process.env.PUBLISHER_TRANSPORT ?? "rabbitmq").toLowerCase(),
+  /** Publish is failed (so the relay retries) if the broker does not confirm within this. */
+  publishTimeoutMs: parseInt(process.env.PAYMENT_PUBLISH_TIMEOUT_MS ?? "10000", 10),
+}));
+
+/**
+ * True when the outbox relay should publish to RabbitMQ rather than POST over HTTP.
+ * RabbitMQ is the default; only an explicit PUBLISHER_TRANSPORT=http opts out.
+ */
+export function isRabbitPublisher(): boolean {
+  return (process.env.PUBLISHER_TRANSPORT ?? "rabbitmq").toLowerCase() !== "http";
+}