Renaming the machine in Tailscale keeps Obeya’s address port-free

When a machine got a new name in the tailnet, Obeya served the new name on port 8443: its entry under the old name was left behind and still held port 443, since Tailscale keeps ports per machine. Obeya now removes its own entry under the old name and serves the new name on the port that entry held, so the phone reaches Obeya at the new name without a port. Entries of other programs stay untouched.