We don't use this column anymore because, when a project is unshared, we simply remove it from the `projects` table. However, this column is expected in the stable version of the server and the database is shared between stable and preview. If we dropped it, stable would start throwing errors.
Zed Server
This crate is what we run at https://collab.zed.dev.
It contains our back-end logic for collaboration, to which we connect from the Zed client via a websocket after authenticating via https://zed.dev, which is a separate repo running on Vercel.