Update AndroidManifest to include foreground service permissions and implement tracking service in excursion screens. Refactor tracking logic to utilize TrackingService for better state management and streamline position updates.

lib/services/tracking_service.dart

@@ -0,0 +1,83 @@
+import 'dart:async';
+
+import 'package:fforte/l10n/app_localizations.dart';
+import 'package:fforte/services/notification_service.dart';
+import 'package:flutter/material.dart';
+import 'package:geolocator/geolocator.dart';
+import 'package:latlong2/latlong.dart';
+
+class TrackingService {
+  static final TrackingService _instance = TrackingService._internal();
+  factory TrackingService() => _instance;
+  TrackingService._internal();
+
+  List<LatLng> pathList = [];
+  StreamSubscription<Position>? positionStream;
+  bool isTracking = false;
+  final _positionController = StreamController<Position>.broadcast();
+
+  Stream<Position> get positionStream$ => _positionController.stream;
+
+  Future<void> startTracking(BuildContext context) async {
+    if (isTracking) return;
+
+    await NotificationService().initNotification();
+    if (context.mounted) {
+    NotificationService().showNotification(
+      title: AppLocalizations.of(context)!.trackingRunningInBackground,
+    );
+    }
+
+    positionStream = Geolocator.getPositionStream(
+      locationSettings: AndroidSettings(
+        accuracy: LocationAccuracy.high,
+        distanceFilter: 0,
+        foregroundNotificationConfig: ForegroundNotificationConfig(
+          notificationTitle: context.mounted ? AppLocalizations.of(context)!.trackingRunningInBackground : "Tracking",
+          notificationText: "",
+        ),
+      ),
+    ).listen((Position? position) {
+      if (position != null) {
+        pathList.add(LatLng(position.latitude, position.longitude));
+        _positionController.add(position);
+      }
+    });
+
+    positionStream!.onError((e) {
+      NotificationService().deleteNotification();
+      NotificationService().showNotification(title: "ERROR: $e");
+    });
+
+    isTracking = true;
+  }
+
+  void pauseTracking() {
+    positionStream?.pause();
+    isTracking = false;
+  }
+
+  void resumeTracking() {
+    positionStream?.resume();
+    isTracking = true;
+  }
+
+  void stopTracking() {
+    positionStream?.cancel();
+    NotificationService().deleteNotification();
+    isTracking = false;
+  }
+
+  void clearPath() {
+    pathList.clear();
+  }
+
+  String getPathAsString() {
+    return pathList.map((pos) => "${pos.latitude},${pos.longitude}").join(";");
+  }
+
+  void dispose() {
+    stopTracking();
+    _positionController.close();
+  }
+}