Focus should support multiple vaporpads per page and per websocket.
The server now has state for tracking multiple vaporpads per connection but protocol changes are still required in order to allow clients to open multiple vaporpads.
Protocol & client changes now allow clients to open multiple vaporpads.
a) the server implements an open()/write() style RPC api (though writes are bidirectional) and
b) the server now plumbs URL paths into generated page HTML to allow generic client JS to know which pad to open based on data-* attributes of the VPP editor container.