More camera -> node, notifications for approaching

lib/models/osm_node.dart

@@ -0,0 +1,54 @@
+import 'package:latlong2/latlong.dart';
+
+class OsmNode {
+  final int id;
+  final LatLng coord;
+  final Map<String, String> tags;
+
+  OsmNode({
+    required this.id,
+    required this.coord,
+    required this.tags,
+  });
+
+  Map<String, dynamic> toJson() => {
+    'id': id,
+    'lat': coord.latitude,
+    'lon': coord.longitude,
+    'tags': tags,
+  };
+
+  factory OsmNode.fromJson(Map<String, dynamic> json) {
+    final tags = <String, String>{};
+    if (json['tags'] != null) {
+      (json['tags'] as Map<String, dynamic>).forEach((k, v) {
+        tags[k.toString()] = v.toString();
+      });
+    }
+    return OsmNode(
+      id: json['id'] is int ? json['id'] as int : int.tryParse(json['id'].toString()) ?? 0,
+      coord: LatLng((json['lat'] as num).toDouble(), (json['lon'] as num).toDouble()),
+      tags: tags,
+    );
+  }
+
+  bool get hasDirection =>
+      tags.containsKey('direction') || tags.containsKey('camera:direction');
+
+  double? get directionDeg {
+    final raw = tags['direction'] ?? tags['camera:direction'];
+    if (raw == null) return null;
+
+    // Keep digits, optional dot, optional leading sign.
+    final match = RegExp(r'[-+]?\d*\.?\d+').firstMatch(raw);
+    if (match == null) return null;
+
+    final numStr = match.group(0);
+    final val = double.tryParse(numStr ?? '');
+    if (val == null) return null;
+
+    // Normalize: wrap negative or >360 into 0‑359 range.
+    final normalized = ((val % 360) + 360) % 360;
+    return normalized;
+  }
+}