add telemetry messages: rx link quality, battery percentage, flight mode, relative altitude

app/lib/transport/mock/mock_flight_controller_link.dart

@@ -11,6 +11,7 @@ class MockFlightControllerLink implements FlightControllerLink {
   StreamController<TelemetryFrame>? _telemetryController;
   Timer? _ticker;
   double _heading = 0;
+  double _batteryPercent = 100;
 
   @override
   FcCapabilities get capabilities => const FcCapabilities(
@@ -28,6 +29,9 @@ class MockFlightControllerLink implements FlightControllerLink {
       // sichtbar ueberprueft werden kann (Doku 9: UI-Entwicklung ohne
       // Hardware).
       _heading = (_heading + 5) % 360;
+      // Langsam sinkender Akkustand, damit die Anzeige auch ohne Hardware
+      // sichtbar auf Werteaenderungen reagiert (Doku 9).
+      _batteryPercent = (_batteryPercent - 0.1).clamp(0, 100);
       _telemetryController?.add(TelemetryFrame(
         lat: 52.5,
         lon: 13.4,
@@ -37,6 +41,11 @@ class MockFlightControllerLink implements FlightControllerLink {
         speedMs: 18,
         headingDeg: _heading,
         armed: _armed,
+        batteryPercent: _batteryPercent.round(),
+        linkQuality: 95,
+        flightMode: _activeWaypointIndex != null
+            ? 'Waypoint mission (en route)'
+            : 'Idle',
         activeWaypointIndex: _activeWaypointIndex,
       ));
     });