Fix the checkout snag.
A validation message, discount field, or address form breaks the flow. Start with one reproducible issue.
The fix, a browser regression, and evidence from desktop and phone.
Use this starter prompt
Reproduce [checkout issue] in [repository] using the sandbox store and test payment method. Fix the root cause and check cart persistence, form errors, and desktop and phone layouts. Add a regression test and show the output and screenshots. Do not place real orders, merge, or deploy.



