Tracking now works via timed interval

lib/services/tracking_service.dart

@@ -6,6 +6,7 @@ import 'package:fforte/services/notification_service.dart';
 import 'package:flutter/material.dart';
 import 'package:geolocator/geolocator.dart';
 import 'package:latlong2/latlong.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class TrackingService {
   static final TrackingService _instance = TrackingService._internal();
@@ -14,8 +15,9 @@ class TrackingService {
 
   List<LatLng> pathList = [];
   List<double> accuracyList = [];
-  StreamSubscription<Position>? positionStream;
+  Timer? _positionTimer;
   bool isTracking = false;
+  BuildContext? _lastContext;
   final _positionController = StreamController<Position>.broadcast();
   final _statsController = StreamController<TrackingStats>.broadcast();
 
@@ -44,34 +46,49 @@ class TrackingService {
   Future<void> startTracking(BuildContext context) async {
     if (isTracking) return;
 
+    _lastContext = context;
     await NotificationService().initNotification();
     NotificationService().showNotification(
       title: AppLocalizations.of(context)!.trackingRunningInBackground,
     );
 
-    positionStream = Geolocator.getPositionStream(
-      locationSettings: AndroidSettings(
-        accuracy: LocationAccuracy.high,
-        distanceFilter: 0,
-        foregroundNotificationConfig: ForegroundNotificationConfig(
-          notificationTitle: AppLocalizations.of(context)!.trackingRunningInBackground,
-          notificationText: "",
-        ),
-      ),
-    ).listen((Position? position) {
-      if (position != null) {
+    // Get tracking interval from settings
+    final prefs = await SharedPreferences.getInstance();
+    final intervalSeconds = prefs.getInt('trackingInterval') ?? 60;
+
+    // Create a timer that triggers position updates
+    _positionTimer = Timer.periodic(Duration(seconds: intervalSeconds), (_) async {
+      try {
+        final Position position = await Geolocator.getCurrentPosition(
+          desiredAccuracy: LocationAccuracy.high,
+        );
+        
         pathList.add(LatLng(position.latitude, position.longitude));
         accuracyList.add(position.accuracy);
         currentAccuracy = position.accuracy;
         _positionController.add(position);
         _updateStats();
+      } catch (e) {
+        NotificationService().deleteNotification();
+        NotificationService().showNotification(title: "ERROR: $e");
       }
     });
 
-    positionStream!.onError((e) {
+    // Get initial position immediately
+    try {
+      final Position position = await Geolocator.getCurrentPosition(
+        desiredAccuracy: LocationAccuracy.high,
+      );
+      
+      pathList.add(LatLng(position.latitude, position.longitude));
+      accuracyList.add(position.accuracy);
+      currentAccuracy = position.accuracy;
+      _positionController.add(position);
+      _updateStats();
+    } catch (e) {
       NotificationService().deleteNotification();
       NotificationService().showNotification(title: "ERROR: $e");
-    });
+    }
 
     isTracking = true;
   }
@@ -131,21 +148,24 @@ class TrackingService {
   }
 
   void pauseTracking() {
-    positionStream?.pause();
+    _positionTimer?.cancel();
     isTracking = false;
   }
 
   void resumeTracking() {
-    positionStream?.resume();
+    if (!isTracking && _lastContext != null) {
+      startTracking(_lastContext!);
+    }
     isTracking = true;
   }
 
   void stopTracking() {
-    positionStream?.cancel();
+    _positionTimer?.cancel();
     NotificationService().deleteNotification();
     isTracking = false;
     accuracyList.clear();
     currentAccuracy = null;
+    _lastContext = null;
   }
 
   void clearPath() {