Restore Shopify Cart Code

I experimented with some AI-generated edits to my Shopify theme and my checkout cart has been unstable ever since. The main symptom is that items in the cart no longer update correctly—quantities stick, removals don’t register, and customers can’t see accurate totals... (Budget: $30 - $250 USD, Jobs: API Integration, Debugging, JavaScript, PHP, Shopify, Shopify Development, Shopify Templates, Web Development)