Public API: set a custom description per quote line when creating a quote

When we create a quote through the /public-api/quote endpoint, we cannot define the description that appears on a quote line. The line item payload only accepts price fields (originalPrice, cost, price, markup, term), so every line gets the description from the product catalog record.

We build quotes from an external system where the line description is often specific to that quote. Today we have to open every quote in the Salesbuildr UI afterwards and edit the descriptions by hand, which defeats the purpose of creating the quote through the API.

What would help:

• an optional description field per line item in the quote create payload that overrides the catalog description for that line only, and

• the same field available when adding or updating lines on an existing quote.

Related: setting a unit price per line via the API is already supported. This is the same idea for the line description.