Embed WebSocket server must fetch bracket on PUB

[mockenoff]

Instead of rerouting information directly from whatever source sends the PUB signal (it'll be the dashboard), the WebSocket embed server should ACK the PUB and then retrieve the bracket model.

This is to avoid packet manipulation if someone manages to decipher the message structure.

Ideally, the Ember dashboard would save via the API, the API would cache, and the embed server would retrieve from the cache.