Function process_message_with_admission 

pub async fn process_message_with_admission(
    config: Config,
    agent_alias: &str,
    message: &str,
    session_id: Option<&str>,
    origin: TurnOrigin,
    execution_admission: Option<AgentExecutionAdmission>,
) -> Result<String>

Process a message with a lease admitted by the caller. Detached producers use this form so the original admission remains owned through delivery and any caller-side persistence instead of being reacquired from a stale input.