Function send_auth_request 

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

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 and sends auth params via the command channel. The handler is responsible for generating the request ID.

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