Function agent_label 

pub fn agent_label<'a>(team: &'a TeamSnapshot, agent_id: &'a str) -> &'a str

Return the operator-facing label for agent_id: the agent’s display_name when set, otherwise agent_id itself. Read-only borrow into the snapshot — callers that need an owned String can .to_string() at the use-site. Unknown ids fall through to agent_id (the canonical id is always a valid label).