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

app/lib/transport/flight_controller_link.dart

@@ -34,6 +34,9 @@ class TelemetryFrame {
     required this.speedMs,
     required this.headingDeg,
     required this.armed,
+    required this.batteryPercent,
+    required this.linkQuality,
+    required this.flightMode,
     this.activeWaypointIndex,
   });
 
@@ -43,6 +46,11 @@ class TelemetryFrame {
   final double lon;
   final bool hasFix;
   final int numSat;
+
+  /// Barometrisch/GPS-fusionierte Hoehe relativ zum Referenzpunkt der
+  /// Positionsschaetzung (in der Praxis: Einschaltort, siehe
+  /// MspNavMode-/estAlt-Doku in msp_telemetry_codec.dart) - keine absolute
+  /// Hoehe ueber Meeresspiegel.
   final double altitudeM;
   final double speedMs;
 
@@ -50,6 +58,17 @@ class TelemetryFrame {
   /// Drohnen-Marker (Doku 3.10, [DroneMarkerIcon]).
   final double headingDeg;
   final bool armed;
+
+  /// Akku-Ladestand in Prozent (0-100).
+  final int batteryPercent;
+
+  /// Empfaenger-Linkqualitaet in Prozent (0-100).
+  final int linkQuality;
+
+  /// Menschenlesbare Kurzbeschreibung des Navigationsmodus (z.B. "Waypoint
+  /// mission (en route)", "Return to home (climbing)", "Idle") - siehe
+  /// MspNavMode.formatted in msp_telemetry_codec.dart.
+  final String flightMode;
   final int? activeWaypointIndex;
 }