List listings by item

List the authenticated seller's active listings for a specific item URN.

This endpoint is useful for item-centric listing management screens where a seller wants all of their offers for one product.

Query and ownership rules:

• Requires urn query parameter.
• Returns only listings owned by the authenticated seller.
• Returns only listings with quantity > 0 (active listings).

Data sources:

• Listing rows are loaded from the primary database.
• Item metadata is enriched from the catalog search index.
• Listing lock state is derived from listing hold records.
• Attachment URLs are attached to each listing in the response.

Response notes:

• If no active listings exist for the provided URN, the API returns an empty array.
• The available quantity in this response mirrors listing quantity.