Vayu Low Stock Counter

Show an honest low stock message on the product page. The block reads each variant's inventory quantity from Shopify and shows "Only 3 left in stock" when the selected variant is at or below your threshold, and updates when the shopper picks another variant. Numbers are never made up. Hide the number and say "Low stock" instead, show an in-stock message above the threshold, add a stock bar, use up to 4 messages by stock level, and set a different threshold per collection.