fix(template/fetch-info): apply discount coupons in storefronts only from URL

Changes coupon storage logic to separate URL coupons from checkout coupons.
Discount is now only applied to product listings when the coupon comes from URL parameters,
while manually applied checkout coupons remain isolated to the checkout flow.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: leomp12

@ecomplus/storefront-template/template/js/lib/fetch-info.js

@@ -1,7 +1,7 @@
 import { modules } from '@ecomplus/client'
 import { price as getPrice } from '@ecomplus/utils'
 import emitter from './emitter'
-import { utm, sessionCoupon } from './persist-utm'
+import { utm, urlCoupon } from './persist-utm'
 
 window._info = window._info || {}
 const fetchInfoPromises = []
@@ -11,7 +11,7 @@ const modulesToFetch = Array.isArray(window.modulesToFetch)
       { endpoint: 'list_payments' },
       { endpoint: 'calculate_shipping' }
     ]
-if (Object.keys(utm).length || sessionCoupon) {
+if (Object.keys(utm).length || urlCoupon) {
   const {
     resource,
     body: contextBody
@@ -27,8 +27,8 @@ if (Object.keys(utm).length || sessionCoupon) {
       }]
     }
   }
-  if (sessionCoupon) {
-    applyDiscountData.discount_coupon = sessionCoupon
+  if (urlCoupon) {
+    applyDiscountData.discount_coupon = urlCoupon
   }
   modulesToFetch.push({
     endpoint: 'apply_discount',

@ecomplus/storefront-template/template/js/lib/persist-utm.js

@@ -19,11 +19,24 @@ if (isCurrentUtm) {
 if (urlParams.get('referral') && !sessionStorage.getItem('ecomReferral')) {
   sessionStorage.setItem('ecomReferral', urlParams.get('referral'))
 }
-const sessionCoupon = urlParams.get('coupon') || sessionStorage.getItem('st_discount_coupon')
-if (sessionCoupon && !sessionStorage.getItem('st_discount_coupon')) {
-  sessionStorage.setItem('st_discount_coupon', sessionCoupon)
+
+const couponStorageKey = 'ecomUrlCoupon'
+const couponCheckoutStorageKey = 'st_discount_coupon'
+const checkoutSessionCoupon = sessionStorage.getItem(couponCheckoutStorageKey)
+let urlCoupon = urlParams.get('coupon')
+if (urlCoupon) {
+  sessionStorage.setItem(couponStorageKey, urlCoupon)
+} else {
+  urlCoupon = sessionStorage.getItem(couponStorageKey)
+  if (checkoutSessionCoupon && urlCoupon && checkoutSessionCoupon !== urlCoupon) {
+    urlCoupon = null
+  }
+}
+const sessionCoupon = urlCoupon || checkoutSessionCoupon
+if (sessionCoupon && !checkoutSessionCoupon) {
+  sessionStorage.setItem(couponCheckoutStorageKey, sessionCoupon)
 }
 
 export default utm
 
-export { utm, sessionCoupon }
+export { utm, sessionCoupon, urlCoupon }