feat: introduce routing status tracking for approved roads and telemetry batch queue limits

apps/siro_maps/lib/core/services/telemetry_tracking_service.dart

@@ -35,6 +35,7 @@ class TelemetryPoint {
         'heading': heading < 0 ? 0.0 : heading,
         'elevation': elevation,
         'distance': distance,
+        'timestamp': timestamp.toUtc().toIso8601String(),
       };
 }
 
@@ -66,7 +67,7 @@ class TelemetryTrackingService {
   List<TelemetryPoint> get bufferedPoints => List.unmodifiable(_buffer);
   DateTime? get lastFlushTime => _lastFlushTime;
 
-  /// Initializes periodic flush timer
+  /// Initializes periodic flush timer for an active navigation session.
   void initialize() {
     _periodicFlushTimer?.cancel();
     _lastFlushTime = DateTime.now();