feat: Enhance map functionality with download area selection and user location pointer

- Added download area selection feature in MapProvider with methods to enter, exit, and update bounds.
- Implemented DownloadAreaOverlay widget for user interface during download area selection.
- Integrated download area preview in MapManagementScreen with visual feedback.
- Introduced LocationPointer widget to indicate user location and heading on the map.
- Updated localization strings in app_sl.arb for improved clarity and accuracy.
- Refactored map marker generation to utilize the new LocationPointer for user location representation.
- Improved error handling in LocationTrackingService for initial position setting.

lib/services/location_tracking_service.dart

@@ -412,9 +412,10 @@ class LocationTrackingService {
       debugPrint('✅ [LocationTracking] Initial position set without broadcast');
       debugPrint('   Next broadcast allowed in ${minTimeIntervalSeconds}s');
     } catch (e) {
-      debugPrint('❌ [LocationTracking] Failed to set initial position: $e');
-      onError?.call('Failed to set initial position: $e');
+      debugPrint('⚠️ [LocationTracking] Failed to set initial position: $e');
+      debugPrint('   Will retry on next GPS update');
       // Don't mark as set on failure, so it will retry on next update
+      // Don't call onError - this is not critical since it will retry automatically
     }
   }