Live location tracking: continuous foreground updates (250m filter) + significant-change background monitoring; list/widget refresh and geofences follow the user, re-fetch on every move

FuelBoard/ContentView.swift

@@ -96,7 +96,7 @@ struct ContentView: View {
             .tabItem { Label("Alerts", systemImage: "bell.fill") }
         }
         .onAppear {
-            locationManager.requestUpdate()
+            locationManager.startForegroundTracking()
             monitor.update(stations: stations, favourites: refreshedFavourites,
                            fuel: selectedFuel, radiusKM: alertsRadius)
             monitor.setEnabled(alertsEnabled)
@@ -104,10 +104,12 @@ struct ContentView: View {
         }
         .onChange(of: scenePhase) { _, newPhase in
             if newPhase == .active {
-                locationManager.requestUpdate()
+                locationManager.startForegroundTracking()
                 monitor.update(stations: stations, favourites: refreshedFavourites,
                                fuel: selectedFuel, radiusKM: alertsRadius)
                 Task { await refresh() }
+            } else {
+                locationManager.stopForegroundTracking()
             }
         }
         .onChange(of: locationManager.current) { _, newLocation in
@@ -123,6 +125,9 @@ struct ContentView: View {
             monitor.setEnabled(newValue)
             monitor.update(stations: stations, favourites: refreshedFavourites,
                            fuel: selectedFuel, radiusKM: alertsRadius)
+            if newValue {
+                locationManager.startBackgroundTracking()
+            }
         }
         .onChange(of: alertsRadius) { _, newValue in
             FuelStore.saveAlertsRadius(newValue)
@@ -284,15 +289,48 @@ final class LocationManager: NSObject, ObservableObject, @preconcurrency CLLocat
         super.init()
         manager.delegate = self
         manager.desiredAccuracy = kCLLocationAccuracyHundredMeters
+        manager.distanceFilter = 250   // metres — re-fires while driving
+        manager.pausesLocationUpdatesAutomatically = true
     }
 
-    func requestUpdate() {
+    /// Continuous tracking while the app is in the foreground, so the list
+    /// re-fetches around the user's new position as they drive.
+    func startForegroundTracking() {
         switch manager.authorizationStatus {
         case .notDetermined:
             manager.requestWhenInUseAuthorization()
             manager.requestLocation()
         case .authorizedWhenInUse, .authorizedAlways:
+            manager.startUpdatingLocation()
+        default:
+            break
+        }
+    }
+
+    /// One-shot fix (first launch / after permission grant).
+    func requestUpdate() {
         manager.requestLocation()
+    }
+
+    /// Background wake-ups on significant movement. Needs Always permission;
+    /// called once the user enables alerts so geofences + prices follow them.
+    func startBackgroundTracking() {
+        guard manager.authorizationStatus == .authorizedAlways else { return }
+        manager.startMonitoringSignificantLocationChanges()
+    }
+
+    func stopForegroundTracking() {
+        // Significant-change monitoring keeps running in the background.
+        manager.stopUpdatingLocation()
+    }
+
+    func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
+        switch manager.authorizationStatus {
+        case .authorizedAlways:
+            manager.startMonitoringSignificantLocationChanges()
+            manager.startUpdatingLocation()
+        case .authorizedWhenInUse:
+            manager.startUpdatingLocation()
         default:
             break
         }