Custom domains: root domains connect on their own, and connections heal themselves

Two fixes for custom domains on Playcode Cloud.

Root domains now go live. A root domain (example.com, not www.example.com) needs one extra verification record at the edge before it can serve over HTTPS. When Playcode runs your DNS - a domain bought here, or one you moved to Playcode nameservers - that record is now added for you the moment you connect, and the edge is asked to check it right away. If your DNS stays at another provider, the connect dialog shows the record beside the routing record, and the assistant lists both.

Connections no longer get lost while you set up DNS. A connection made before a nameserver change had finished could be dropped as abandoned. Playcode now keeps every connection you make, checks it against the edge every few minutes, and restores it automatically while your domain points at Playcode. If a domain never points at Playcode for a week, you get one email and can reconnect any time.

The Domains settings and the assistant's domain status now say what the edge actually serves, not only whether DNS has landed.