feat: check category eligibility for update discount in frontend and backend

shop/components/order-wizard.tsx

@@ -353,16 +353,14 @@ export function OrderWizard({
         })
         const totalItem = base + modulesSum
         if (prod.billing_interval === 'one_time') {
-          oneTime += totalItem
+          const allowDiscount = (cat as any).allow_update_discount !== false
+          const finalItemTotal = allowDiscount ? (totalItem * updatePriceModifier.multiplier) : totalItem
+          oneTime += finalItemTotal
         } else {
           monthly += totalItem
         }
       })
     }
-    // Apply update modifier to oneTime total
-    if (updatePriceModifier.multiplier !== 1) {
-      oneTime = oneTime * updatePriceModifier.multiplier
-    }
     return { monthlyTotal: monthly, oneTimeTotal: oneTime }
   }, [selections, products, categories, moduleQuantities, updatePriceModifier])