Fix guest checkout showing "Order not found" on order-placed page (#32)

Skip CartProvider's refreshCart() on the order-placed page to prevent
a race condition where getCart() auto-clears the _spree_cart_token
cookie before getCheckoutOrder() can use it. For guest users this
token is the only authentication — once cleared, the API returns
nothing and the confirmation page shows "Order not found."

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: Cichorek

src/contexts/CartContext.tsx

@@ -116,9 +116,17 @@ export function CartProvider({ children }: { children: ReactNode }) {
   );
 
   // Re-fetch cart on navigation (e.g., after checkout completes, the stale
-  // cart token will be cleared by getCart and the cart state will update)
-  // biome-ignore lint/correctness/useExhaustiveDependencies: pathname triggers re-fetch on navigation
+  // cart token will be cleared by getCart and the cart state will update).
+  // On the order-placed page, skip refreshCart to avoid a race condition:
+  // getCart() auto-clears the cart token cookie on error (completed order
+  // is no longer a cart), which removes the only auth token guest users
+  // have before getCheckoutOrder() can use it.
   useEffect(() => {
+    if (pathname.includes("/order-placed/")) {
+      setCart(null);
+      setLoading(false);
+      return;
+    }
     refreshCart();
   }, [refreshCart, pathname]);