Function send_auth_request 

pub fn send_auth_request(
    credential: &Credential,
    scope: Option<String>,
    cmd_tx: &UnboundedSender<HandlerCommand>,
    request_id_counter: &Arc<AtomicU64>,
)

Sends an authentication request using client_signature grant type.

This is a helper function used by both initial authentication and re-authentication after reconnection. It generates the signature, creates the JSON-RPC request, and sends it via the command channel.

Arguments

• credential - API credentials for signing the request
• scope - Optional scope (e.g., “session:nautilus” for session-based auth)
• cmd_tx - Command channel to send the authentication request
• request_id_counter - Counter for generating unique request IDs