Add websocket support

[m4tx]

Since websockets are so widespread nowadays, it's a must to implement them. We should get a first-class support for websockets at some point.

It's also worth considering if it makes sense to integrate stuff built on websockets, such as:

• socketioxide

[xerion12]

hey @m4tx, websocket support would be awesome to have. i’ve worked with async websockets in rust before tokio-tungstenite, axum, and socketioxide and built real-time endpoints for chat and notification systems. i’d be happy to help design or implement the initial websocket integration here, maybe start with a simple connection + message handler and expand from there.