feat(payment-stripe): merge custom metadata along with session_id on payment initiation (medusajs#13801)

* Merge custom metadata along with session_id on payment initiation

* update changeset

Author: vethan

.changeset/cool-brooms-travel.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/payment-stripe": patch
+---
+
+feat(payment-stripe): merge custom metadata along with session_id on payment initiation

packages/modules/providers/payment-stripe/src/core/stripe-base.ts

@@ -248,7 +248,7 @@ abstract class StripeBase extends AbstractPaymentProvider<StripeOptions> {
     const intentRequest: Stripe.PaymentIntentCreateParams = {
       amount: getSmallestUnit(amount, currency_code),
       currency: currency_code,
-      metadata: { session_id: data?.session_id as string },
+      metadata: { ...(data?.metadata ?? {}), session_id: data?.session_id as string },
       ...additionalParameters,
     }