Remove Browsersync

[JeffreyATW]

Browsersync does absolutely nothing besides making local dev setup difficult, so out it goes.

This PR also solves a problem where the WebSockets server and the vanilla HTTP server shared the same port. They will still share the same port (and somehow not cause issues) on prod, but locally the WS server will always operate on 3010 (and thanks to the removal of BS, the HTTP server will always operate on 3000).

In a future PR, I'll create only a single listener for both WS and HTTP.

[holetse]

👋 BrowserSync

[JeffreyATW]

A follow-up on this PR's description:

Only one server runs on prod. The express-ws package does the work of upgrading requests when necessary.

On dev, start.ts runs a secondary server to handle hot module reloading and other stuff, but allows the underlying app (also running its own server) to handle requests. Probably not necessary to merge into one - local dev works fine now.