List a shipment's legs in transport-path order — the first mile first, then each onward leg, so no leg is listed before a leg it depends on. Order is derived from the addresses, not stored: a split writes every leg in one transaction, so creation time cannot express the journey. Each leg carries its position: how many handovers separate it from the shipment's own pickup, where 0 is the first mile. Legs that leave the same address in parallel (a split across several tours) share a position and keep creation order between them; a leg the transport path cannot reach carries no position at all. This is the only leg listing that reports position — the tenant-wide and tour-scoped listings have no shipment leg set to derive it from. A shipment carries a small, bounded number of legs, so the complete set is returned in a single page (no pagination cursor).