Function handle_agent_identity_accounts 

pub(super) async fn handle_agent_identity_accounts(
    __arg0: State<AppState>,
    caller: Option<Extension<Caller>>,
    __arg2: Query<AgentIdentityAccountsQuery>,
) -> impl IntoResponse

GET /api/v1/agent/identity/accounts?agent_id=<slug> — list the agent’s own linked credential accounts (masked tails only, never secrets). Backs the IdentityAccounts MCP tool.