fix(admin): name the configured geo provider in the system snapshot

The admin system snapshot hardcoded "ipwho.is" for the offline-geo-off
state, so an operator who points IP_GEO_LOOKUP_URL at another provider
still read the wrong host. Resolve the actual provider host from the env
and surface it through /api/version, so the snapshot reads
"Online (ip-api.com)" — the host it really queries.

src/components/admin/_shared.tsx

@@ -500,6 +500,10 @@ export interface PublicVersion {
   buildSha: string | null;
   builtAt: string | null;
   offlineGeoEnabled?: boolean;
+  // Host of the online geo provider the runtime falls back to when the
+  // offline tier is absent (host of IP_GEO_LOOKUP_URL, default ipwho.is).
+  // Optional so legacy /api/version responses still satisfy the shape.
+  geoProviderHost?: string;
 }
 
 /** Shared `/api/version` reader — the system-status section + overview

src/components/admin/system-status-section.tsx

@@ -169,7 +169,9 @@ export function SystemStatusSection() {
                 value={
                   version.offlineGeoEnabled
                     ? t("admin.offlineGeoEnabled")
-                    : t("admin.offlineGeoFallback")
+                    : t("admin.offlineGeoFallback", {
+                        host: version.geoProviderHost ?? "ipwho.is",
+                      })
                 }
                 className={
                   version.offlineGeoEnabled

src/components/admin/system-status-summary.tsx

@@ -106,7 +106,9 @@ export function SystemStatusSummary() {
               value={
                 version.offlineGeoEnabled
                   ? t("admin.overview.snapshotOfflineGeoOn")
-                  : t("admin.overview.snapshotOfflineGeoOff")
+                  : t("admin.overview.snapshotOfflineGeoOff", {
+                      host: version.geoProviderHost ?? "ipwho.is",
+                    })
               }
               className={
                 version.offlineGeoEnabled