MCP search_shop_catalog: availabilityMatrix includes variants with zero inventory

When using search_shop_catalog, the availabilityMatrix field is inconsistent with actual inventory.

Current behavior:

  • availabilityMatrix lists variants that exist in options

  • Some variants in availabilityMatrix have zero inventory

Expected behavior:

  • availabilityMatrix should only include variants with available inventory

  • Variants with zero inventory should not appear in availabilityMatrix

Impact:

  • Misleads customers about product availability

  • Requires extra get_product_details checks to verify stock

  • Disrupts availability-based filtering