modify slice to account for items with variants

src/utils/types/appTypes.ts

@@ -328,6 +328,8 @@ export interface CartItem {
   isHasLoyalty?: boolean;
   no_of_stamps_give?: number;
   comment?: string;
+  // Unique identifier for cart items with the same product but different variants/extras/comments
+  uniqueId?: string;
 }
 
 export interface User {