Widget: per-widget distance, sanitised names, £ prices

- New Distance picker in Edit Widget (5/10/15 miles), independent of the
  app's distance filter; used for both the relay fetch radius and the
  strict in-widget filter.
- Brand text is now title-cased via sanitizedStationTitle (relay sends
  all-caps brands like SHELL/TESCO/MORRISONS).
- Prices now show as £1.399 (monospaced) matching the app, instead of
  139.9p.
- Directions deep-link (mapsDirectionsURL) already per-row on medium and
  whole-widget on small; unchanged. 35 tests pass.

FuelBoardWidgets/WidgetConfigIntent.swift

@@ -33,13 +33,38 @@ enum WidgetSort: String, AppEnum, CaseIterable, Codable {
     ]
 }
 
+enum WidgetDistance: String, AppEnum, CaseIterable, Codable {
+    case five
+    case ten
+    case fifteen
+
+    static var typeDisplayRepresentation: TypeDisplayRepresentation = "Distance"
+
+    static var caseDisplayRepresentations: [WidgetDistance: DisplayRepresentation] = [
+        .five: "5 miles",
+        .ten: "10 miles",
+        .fifteen: "15 miles",
+    ]
+
+    var miles: Int {
+        switch self {
+        case .five: return 5
+        case .ten: return 10
+        case .fifteen: return 15
+        }
+    }
+}
+
 struct FuelBoardWidgetConfigurationIntent: WidgetConfigurationIntent {
     static var title: LocalizedStringResource = "Fuel & Sort"
-    static var description = IntentDescription("Which fuel and ordering this widget shows.")
+    static var description = IntentDescription("Which fuel, ordering and search radius this widget shows.")
 
     @Parameter(title: "Fuel", default: .e10)
     var fuel: WidgetFuel
 
     @Parameter(title: "Sort by", default: .cheapest)
     var sort: WidgetSort
+
+    @Parameter(title: "Distance", default: .five)
+    var distance: WidgetDistance
 }