What is the ruling on saying "So-and-so sells flatbread" without the intention of disparagement or pointing to a specific person, and what is the ruling on saying "So-and-so sells sunflower seeds" with the intention that they are from the people who sell sunflower seeds? Is this considered forbidden backbiting?

Merely informing about someone that he sells something is not forbidden backbiting, unless he dislikes that. For backbiting is: "Your mentioning your brother with what he dislikes." And scholars used to title some of themselves by their relation to what they sold (like al-Khawwas and al-Dabbagh), and they did not consider that backbiting.