Fix widget distance menu + geofence notification chain

Widget distance menu: the Distance picker only makes sense for
Cheapest ordering. It was hidden for Favourites but Closest still
showed it (regressed when the per-widget Distance picker was added).
parameterSummary now nests When clauses: Distance visible for
Cheapest only; Closest and Favourites hide it.

Notifications: three compounding defects kept real geofence alerts
from ever firing while the app was suspended:

1. Always permission was never properly requested. requestPermissions
   fired WhenInUse and Always back-to-back; iOS ignores the second
   call while the first prompt is pending, leaving the app stuck on
   WhenInUse — and region entries are never delivered in the
   background. Added locationManagerDidChangeAuthorization to
   ProximityMonitor: escalate WhenInUse -> Always, and re-register
   geofences on grant (regions registered under WhenInUse-only won't
   deliver in the background).

2. The 18-region window was frozen in the background. Re-registration
   lived in SwiftUI .onChange(of: locationManager.current), which
   never runs while suspended. Added a delegate hook
   (LocationManager.onLocationUpdate) fired from didUpdateLocations on
   every fix including background significant-change wake-ups; the app
   wires it to re-register geofences around the new position.

3. Region-registration failures were invisible. monitoringDidFailFor
   was never implemented, so a failed startMonitoring (region budget,
   auth, radius) silently stopped alerts. Now surfaced as
   monitor.lastRegionError and shown in Settings -> Debug; cleared on
   the next successful registration.

FuelBoard/ContentView.swift

@@ -179,6 +179,16 @@ struct ContentView: View {
             // network fetch start once it's done.
             if FuelStore.loadHasCompletedOnboarding() {
                 locationManager.startForegroundTracking()
+                // Geofences must follow the user even in the background:
+                // wire the delegate hook (fires on every fix incl. background
+                // significant-change wake-ups) to re-register the region
+                // window around the new position. SwiftUI onChange alone
+                // never runs while suspended, so alerts would otherwise stay
+                // frozen around the last foreground fix.
+                locationManager.onLocationUpdate = { [weak monitor] in
+                    monitor?.update(stations: stations, favourites: refreshedFavourites,
+                                    fuel: alertsFuel, radiusKM: alertsRadius)
+                }
                 monitor.update(stations: stations, favourites: refreshedFavourites,
                                fuel: alertsFuel, radiusKM: alertsRadius)
                 monitor.setEnabled(alertsEnabled)
@@ -277,7 +287,8 @@ struct ContentView: View {
             onRefreshDebugStatus: { monitor.refreshDebugStatus() },
             onShowOnboarding: { showOnboarding = true },
             debugStatus: monitor.debugStatus,
-            appCheapest: appCheapestStatus
+            appCheapest: appCheapestStatus,
+            regionError: monitor.lastRegionError
         )
         .tabItem { Label("Settings", systemImage: "gearshape.fill") }
     }
@@ -457,6 +468,12 @@ struct StationRow: View {
 @MainActor
 final class LocationManager: NSObject, ObservableObject, @preconcurrency CLLocationManagerDelegate {
     @Published var current: Coordinate?
+    /// Called after every location fix (foreground AND background wake-ups).
+    /// The app uses it to re-register geofences around the new position —
+    /// SwiftUI's `.onChange` never runs in the background, so this delegate
+    /// hook is the only path that keeps the 18-region window following the
+    /// user while driving with the app suspended.
+    var onLocationUpdate: (() -> Void)?
     private let manager = CLLocationManager()
 
     override init() {
@@ -522,6 +539,10 @@ final class LocationManager: NSObject, ObservableObject, @preconcurrency CLLocat
             lastWidgetReload = now
             WidgetCenter.shared.reloadAllTimelines()
         }
+        // Re-register geofences around the new position. Also fires on
+        // background significant-change wake-ups, which SwiftUI onChange
+        // never sees — this is what keeps alerts working while driving.
+        onLocationUpdate?()
     }
 
     private var lastWidgetReload = Date.distantPast

FuelBoard/ProximityMonitor.swift

@@ -65,6 +65,10 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
     /// Debug-only snapshot for the Settings → Debug section. Recomputed on
     /// every location/stations change via `refreshDebugStatus()`.
     @Published private(set) var debugStatus: DebugLocationStatus?
+    /// Last CoreLocation region-monitoring failure, if any. Shown in Settings
+    /// → Debug so a silently-failed `startMonitoring` (region budget exceeded,
+    /// auth not granted, radius too large) is visible instead of invisible.
+    @Published private(set) var lastRegionError: String?
 
     private let manager = CLLocationManager()
     private var stations: [FuelStation] = []
@@ -117,6 +121,10 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
 
         guard enabled else { return }
 
+        // A successful re-registration pass resets any earlier failure so the
+        // Debug section only shows the CURRENT region problem.
+        lastRegionError = nil
+
         // Favourites first (guaranteed slots), then closest stations, max 18.
         // `self.favourites` is already filtered to the monitored fuel.
         var candidates: [FuelStation] = self.favourites
@@ -198,10 +206,14 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
 
     private func requestPermissions() {
         // Region monitoring needs Always location for background delivery.
+        // Never request WhenInUse and Always back-to-back — iOS ignores the
+        // second call while the first prompt is pending, leaving the app
+        // stuck on WhenInUse and background geofence entries undelivered.
+        // Escalation happens in locationManagerDidChangeAuthorization:
+        // WhenInUse granted -> request Always -> re-register on grant.
         switch manager.authorizationStatus {
         case .notDetermined:
             manager.requestWhenInUseAuthorization()
-            manager.requestAlwaysAuthorization()
         case .authorizedWhenInUse:
             manager.requestAlwaysAuthorization()
         default:
@@ -210,6 +222,25 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
         UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { _, _ in }
     }
 
+    func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
+        switch manager.authorizationStatus {
+        case .authorizedWhenInUse:
+            // Escalate: background region delivery (the whole point of
+            // alerts) requires Always. iOS shows the upgrade prompt here.
+            manager.requestAlwaysAuthorization()
+        case .authorizedAlways:
+            // Regions registered under WhenInUse-only won't deliver in the
+            // background; re-register now that Always is granted. (ContentView's
+            // LocationManager separately restarts significant-change tracking
+            // on its own delegate callback, so the region window follows the
+            // user in the background.)
+            update(stations: stations, favourites: FuelStore.loadFavourites(),
+                   fuel: fuel, radiusKM: radiusKM)
+        default:
+            break
+        }
+    }
+
     // MARK: - Region events
 
     nonisolated func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
@@ -222,6 +253,20 @@ final class ProximityMonitor: NSObject, ObservableObject, @preconcurrency CLLoca
         // Ignore — alerts still work while the app is open.
     }
 
+    nonisolated func locationManager(
+        _ manager: CLLocationManager,
+        monitoringDidFailFor region: CLRegion?,
+        withError error: Error
+    ) {
+        Task { @MainActor in
+            // Surface region-registration failures instead of swallowing
+            // them: a failed startMonitoring (region budget, auth, radius)
+            // means alerts silently stop. Cleared on the next successful
+            // re-registration (update() resets it).
+            lastRegionError = "\(region?.identifier ?? "?") · \(error.localizedDescription)"
+        }
+    }
+
     private func handleEntry(_ region: CLRegion) {
         let stationID = region.identifier
         // Fall back to cached data on background wake (stations may not be

FuelBoard/SettingsView.swift

@@ -30,8 +30,11 @@ struct SettingsView: View {
     /// Live snapshot of the device fix + stations in range (from the monitor).
     var debugStatus: DebugLocationStatus?
     /// The app's own TOP-badge cheapest (selected fuel + stationLimit radius),
-    /// so the debug "Cheapest in range" row matches the app list exactly.
+    /// passed in so the Debug section mirrors the app list exactly.
     var appCheapest: DebugAppCheapest?
+    /// Last CoreLocation region-monitoring failure (monitor.lastRegionError).
+    /// Shown in Debug so a silently-failed geofence registration is visible.
+    var regionError: String?
 
     @StateObject private var tipStore = TipStore()
     @State private var showTipAlert = false
@@ -90,6 +93,11 @@ struct SettingsView: View {
                                 .font(.footnote)
                                 .foregroundStyle(.green)
                         }
+                        if let regionError {
+                            Label(regionError, systemImage: "exclamationmark.triangle.fill")
+                                .font(.footnote)
+                                .foregroundStyle(.red)
+                        }
                         Button {
                             onPlainTestAlert()
                         } label: {

FuelBoardWidgets/WidgetConfigIntent.swift

@@ -70,19 +70,27 @@ struct FuelBoardWidgetConfigurationIntent: WidgetConfigurationIntent {
     @Parameter(title: "Distance", default: .five)
     var distance: WidgetDistance
 
-    /// Edit-Widget UI: Favourites ranks pinned stations cheapest-first and is
+    /// Edit-Widget UI: the Distance picker only makes sense for Cheapest
-    /// not radius-bound, so the Distance picker is hidden in that mode.
+    /// ordering — Closest is inherently "nearest within range" and Favourites
+    /// is not radius-bound. Show it for Cheapest only; hide for both others.
     static var parameterSummary: some ParameterSummary {
+        When(\.$sort, .equalTo, WidgetSort.cheapest) {
+            Summary("Show \(\.$fuel) by \(\.$sort) within \(\.$distance)") {
+                \.$fuel
+                \.$sort
+                \.$distance
+            }
+        } otherwise: {
             When(\.$sort, .equalTo, WidgetSort.favourites) {
                 Summary("Show \(\.$fuel) favourites") {
                     \.$fuel
                     \.$sort
                 }
             } otherwise: {
-            Summary("Show \(\.$fuel) by \(\.$sort) within \(\.$distance)") {
+                Summary("Show \(\.$fuel) by \(\.$sort)") {
                     \.$fuel
                     \.$sort
-                \.$distance
+                }
             }
         }
     }