We've simplified the experience for finding other Zed users with whom you want to collaborate.
You can open a contact search modal via a button at the top of the contacts panel.
When you make a request, the other user is notified.
Once someone is your contact, they are free to join any project that you are sharing. We'll be following up in the next release to restrict this a bit so that you're prompted before your contacts are allowed access. We expect to refine this permissions system over time, but for now, prompting feels like a safe compromise.
We also fixed a bug where multi-cursor editing in multi-buffers could insert repeated characters in some cases.