fix: Prevent invalid map bounds #123

test/models/custom_map_config_test.dart

@@ -0,0 +1,37 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:latlong2/latlong.dart';
+import 'package:meshcore_sar_app/models/custom_map_config.dart';
+
+void main() {
+  test('displayBounds stays within valid LatLng limits for tall images', () {
+    const config = CustomMapConfig(
+      filePath: '/tmp/map.png',
+      displayName: 'Tall Map',
+      mapId: 'map-id',
+      imageWidth: 2400,
+      imageHeight: 3213,
+    );
+
+    expect(config.displayBounds.north, lessThanOrEqualTo(90));
+    expect(config.displayBounds.south, greaterThanOrEqualTo(-90));
+    expect(config.displayBounds.east, lessThanOrEqualTo(180));
+    expect(config.displayBounds.west, greaterThanOrEqualTo(-180));
+  });
+
+  test('display point conversion preserves stored coordinates', () {
+    const config = CustomMapConfig(
+      filePath: '/tmp/map.png',
+      displayName: 'Tall Map',
+      mapId: 'map-id',
+      imageWidth: 2400,
+      imageHeight: 3213,
+    );
+    const storedPoint = LatLng(1600, 1200);
+
+    final displayPoint = config.toDisplayPoint(storedPoint);
+    final roundTrip = config.fromDisplayPoint(displayPoint);
+
+    expect(roundTrip.latitude, closeTo(storedPoint.latitude, 0.001));
+    expect(roundTrip.longitude, closeTo(storedPoint.longitude, 0.001));
+  });
+}