Browser-like WebSocket client API for Elixir.

Events are delivered as messages to the owner process:

{HTTP.WebSocket, socket, %HTTP.WebSocket.Event.Open{}}
{HTTP.WebSocket, socket, %HTTP.WebSocket.Event.Message{}}
{HTTP.WebSocket, socket, %HTTP.WebSocket.Event.Error{}}
{HTTP.WebSocket, socket, %HTTP.WebSocket.Event.Close{}}

HTTP/1 is the default. Select http_version: :http2, :h2c, or :auto explicitly; http_version/1 reports the negotiated HTTP version, while protocol/1 continues to report the selected WebSocket subprotocol.

With delivery: :ack, message events include a delivery reference:

{HTTP.WebSocket, socket, %HTTP.WebSocket.Event.Message{}, ref}

Call acknowledge/2 after consuming each message. Open, Error, and Close retain their three-element event envelopes. Receive queues, pending sends, and fragmented messages have finite configurable limits. Established sessions default to idle_timeout: :infinity; opening and close deadlines are separate.

Plain Elixir binaries are sent as text frames. Use array_buffer/1 or HTTP.Blob for binary frames.

For wss connections, pass tls_backend: :ssl | :ex_ssl (or the equivalent string in a map). When omitted, the shared :http_core TLS backend setting is captured when the socket is created.