Cart fixes (backend), adjusted header, added footer, mobile formatting updates

web/lib/cartApi.js

@@ -91,3 +91,12 @@ export async function apiCompleteCheckout(token, paymentIntentId) {
 
   return handleResponse(res);
 }
+
+export async function apiCancelCheckout(token, storeId) {
+  const res = await fetch(`${BASE}/checkout/cancel?storeId=${storeId}`, {
+    method: "POST",
+    headers: authHeaders(token),
+  });
+
+  return handleResponse(res);
+}