Fix: Approve & Add to Bag button not working

- Add JSON body to approve API request
- Add Content-Type header
- Add error handling with user-friendly messages
- Log errors to console for debugging

The button now properly sends the approval request and adds
the design to the customer's bag.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

.claude/settings.local.json

@@ -165,7 +165,8 @@
       "Bash(git commit -m 'Revert: Remove loading spinner - was slowing down page *)",
       "Bash(git commit -m 'Fix: Show approved designs in customer account so they can order *)",
       "Bash(git commit -m 'Fix: Link approved designs to review page, not personalization *)",
-      "Bash(git commit -m 'Feat: Show estimated delivery date on design review page *)"
+      "Bash(git commit -m 'Feat: Show estimated delivery date on design review page *)",
+      "Bash(git commit -m 'Fix: Approve & Add to Bag button not working *)"
     ]
   }
 }