Protocol v1 WebSocket client for the native endpoint (/socket/converger/v1), built on Mint.WebSocket.

{:ok, sock} =
  ConvergerClient.Socket.start_link(
    client: client,                 # or url: "wss://host/socket/converger/v1"
    token: conversation_token,      # or a 0-arity function returning one
    conversation_id: conversation_id,
    watermark: stored_watermark
  )

{:ok, %ConvergerClient.Ack{seq: seq}} = ConvergerClient.Socket.send_text(sock, "Hello")

receive do
  {:converger, ^sock, %{"type" => "text", "data" => %{"text" => text}}} -> text
end

Frames for the application are sent to the owner (the caller of start_link/1, or :owner) as {:converger, socket, frame}: persistent frames in seq order, exactly once, plus transient frames (typing, presence, receipts, errors) and every welcome. When the socket ends for good the owner receives {:converger_closed, socket, %{code: code, reason: reason}} and the process stops.

The socket reconnects with jittered exponential backoff, resumes from the watermark, answers gaps with sync, and re-sends unacknowledged sends with their original clientId (exactly-once persistence on the server).