This PR simplifies our state management for channels, and logic for inheriting channel permissions, by removing the ability for channels to have multiple parent channels.
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.