Returns a candidate profile by its Popp id. Organization context is taken from the authenticated API key, never from the path. A candidate that does not exist and one that belongs to a different organization group both return 404 — the two are deliberately not distinguished, so an id cannot be probed against another tenant. The response carries the canonical fields alongside a fromCv block holding what CV parsing extracted; those are read-only and may differ from the canonical values where a caller has supplied its own. location.geoCoordinates is populated asynchronously by processing, so a candidate read shortly after a create may carry a location with no coordinates yet.