first version worth putting in git - compiles and runs - missing a lot still.

lib/services/overpass_service.dart

@@ -0,0 +1,54 @@
+import 'dart:convert';
+
+import 'package:http/http.dart' as http;
+import 'package:flutter_map/flutter_map.dart';   // LatLngBounds
+import 'package:latlong2/latlong.dart';         // LatLng
+
+import '../models/camera_profile.dart';
+import '../models/osm_camera_node.dart';
+
+class OverpassService {
+  static const _endpoint = 'https://overpass-api.de/api/interpreter';
+
+  Future<List<OsmCameraNode>> fetchCameras(
+    LatLngBounds bbox,
+    List<CameraProfile> profiles,
+  ) async {
+    if (profiles.isEmpty) return [];
+
+    // Combine enabled profile types into a regex
+    final types = profiles
+        .map((p) => p.tags['surveillance:type'])
+        .whereType<String>()
+        .toSet();
+    final regex = types.join('|');
+
+    final query = '''
+      [out:json][timeout:25];
+      (
+        node
+          ["man_made"="surveillance"]
+          ["surveillance:type"~"^(${regex})\$"]
+          (${bbox.southWest.latitude},${bbox.southWest.longitude},
+           ${bbox.northEast.latitude},${bbox.northEast.longitude});
+      );
+      out body 100;
+    ''';
+
+    final resp =
+        await http.post(Uri.parse(_endpoint), body: {'data': query.trim()});
+    if (resp.statusCode != 200) return [];
+
+    final data = jsonDecode(resp.body) as Map<String, dynamic>;
+    final elements = data['elements'] as List<dynamic>;
+
+    return elements.whereType<Map<String, dynamic>>().map((e) {
+      return OsmCameraNode(
+        id: e['id'],
+        coord: LatLng(e['lat'], e['lon']),
+        tags: Map<String, String>.from(e['tags'] ?? {}),
+      );
+    }).toList();
+  }
+}
+