Returns the set of network providers the FE should offer on the signup form for the currentNetwork field. Order in the array is the canonical display order — render as-is.

Each item carries a stable value (submit verbatim on signup) and a label (display text owned by the backend so wording can change without an app release). The stable MVNO value uses the tenant app display name as its label. To add a new provider we update the enum + display map server-side; the FE picks it up on the next dropdown load. Cached for 5 minutes.

Access: Public endpoint.