Function run_once_in_session 

pub async fn run_once_in_session(
    session_manager: &SessionManager,
    session_id: String,
    message: String,
) -> Result<RunOnceResult>

Runs the agent once in an existing session.

• session_manager – SessionManager instance to use
• session_id – ID of the existing session to use
• message – user message to process
• timeout – optional wall-clock limit