Fix lat/lng double decoding issue

lib/models/device.dart

@@ -70,8 +70,8 @@ class Device {
       colorcode: json['colorcode'] as int?,
       status: json['status'] as int?,
       lastKnownMaster: json['last_known_master'] as int?,
-      lat: json['lat'] as double?,
-      lng: json['lng'] as double?,
+      lat: _toDouble(json['lat']),
+      lng: _toDouble(json['lng']),
       website: json['website'] as String?,
       pep: json['pep'] as int?,
       agl: json['agl'] as int?,
@@ -85,6 +85,14 @@ class Device {
     );
   }
 
+  static double? _toDouble(dynamic value) {
+    if (value == null) return null;
+    if (value is double) return value;
+    if (value is int) return value.toDouble();
+    if (value is String) return double.tryParse(value);
+    return null;
+  }
+
   Map<String, dynamic> toJson() {
     return {
       'id': id,