Function rename_jobs_by_agent 

pub fn rename_jobs_by_agent(
    config: &Config,
    from: &str,
    to: &str,
) -> Result<usize>

Re-point every cron job owned by from to to, returning the row count. Called by the agent-rename cascade the job keeps running, just under the renamed owner. agent_alias is plain TEXT (not a UUID), so this is a direct column update.