feat: MeshCore SAR - Flutter BLE mesh radio companion app

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/models/contact_telemetry.dart

@@ -0,0 +1,76 @@
+import 'package:latlong2/latlong.dart';
+
+/// Contact telemetry data from MeshCore device
+class ContactTelemetry {
+  final LatLng? gpsLocation;
+  final double? batteryPercentage;
+  final double? batteryMilliVolts;
+  final double? temperature;
+  final DateTime timestamp;
+
+  // Additional sensor data
+  final double? humidity;
+  final double? pressure;
+  final Map<String, dynamic>? extraSensorData;
+
+  ContactTelemetry({
+    this.gpsLocation,
+    this.batteryPercentage,
+    this.batteryMilliVolts,
+    this.temperature,
+    required this.timestamp,
+    this.humidity,
+    this.pressure,
+    this.extraSensorData,
+  });
+
+  /// Check if telemetry data is recent (within last 5 minutes)
+  bool get isRecent {
+    return DateTime.now().difference(timestamp).inMinutes < 5;
+  }
+
+  /// Check if battery level is low (< 20%)
+  bool get isLowBattery {
+    return batteryPercentage != null && batteryPercentage! < 20.0;
+  }
+
+  /// Check if battery level is critical (< 10%)
+  bool get isCriticalBattery {
+    return batteryPercentage != null && batteryPercentage! < 10.0;
+  }
+
+  /// Get battery status color indicator
+  String get batteryStatus {
+    if (batteryPercentage == null) return 'unknown';
+    if (batteryPercentage! > 50) return 'good';
+    if (batteryPercentage! > 20) return 'medium';
+    return 'low';
+  }
+
+  ContactTelemetry copyWith({
+    LatLng? gpsLocation,
+    double? batteryPercentage,
+    double? batteryMilliVolts,
+    double? temperature,
+    DateTime? timestamp,
+    double? humidity,
+    double? pressure,
+    Map<String, dynamic>? extraSensorData,
+  }) {
+    return ContactTelemetry(
+      gpsLocation: gpsLocation ?? this.gpsLocation,
+      batteryPercentage: batteryPercentage ?? this.batteryPercentage,
+      batteryMilliVolts: batteryMilliVolts ?? this.batteryMilliVolts,
+      temperature: temperature ?? this.temperature,
+      timestamp: timestamp ?? this.timestamp,
+      humidity: humidity ?? this.humidity,
+      pressure: pressure ?? this.pressure,
+      extraSensorData: extraSensorData ?? this.extraSensorData,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'ContactTelemetry(gps: $gpsLocation, battery: $batteryPercentage%, temp: $temperature°C, time: $timestamp)';
+  }
+}