Results filter is now search radius in miles (5/10/15); relay fetch scoped to radius, limit 500; changing miles re-fetches; caption shows stations within N miles

FuelBoard/StationsView.swift

@@ -80,9 +80,9 @@ struct StationsView: View {
 
                     if !stations.isEmpty {
                         Divider()
-                        Picker("Show", selection: $stationLimit) {
-                            ForEach([10, 25, 50, 75, 100], id: \.self) { count in
-                                Text("\(count)").tag(count)
+                        Picker("Within", selection: $stationLimit) {
+                            ForEach(FuelStore.stationRadiusOptions, id: \.self) { miles in
+                                Text("\(miles) miles").tag(miles)
                             }
                         }
                         .pickerStyle(.segmented)
@@ -90,7 +90,7 @@ struct StationsView: View {
                             FuelStore.saveStationLimit(newValue)
                         }
                         .padding(.vertical, 2)
-                        Text("Showing \(stations.count) of \(totalCount) stations")
+                        Text("\(totalCount) stations within \(stationLimit) miles")
                             .font(.caption2)
                             .foregroundStyle(.secondary)
                     }