Extract settings and harden geofence automation

test/settings_service_test.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 
 import 'package:flutter_test/flutter_test.dart';
+import 'package:ignis_app/features/settings/models/app_theme_preset.dart';
 import 'package:ignis_app/models/home_config.dart';
 import 'package:ignis_app/services/credentials_storage.dart';
 import 'package:ignis_app/services/settings_service.dart';
@@ -79,4 +80,18 @@ void main() {
         jsonDecode(prefs.getString('ignis_homes')!) as List<dynamic>;
     expect(storedHomes.single, isNot(contains('apiKey')));
   });
+
+  test('stores and restores app theme preset', () async {
+    SharedPreferences.setMockInitialValues({});
+
+    final service = SettingsService(
+      credentialsStorage: InMemoryCredentialsStorage(),
+    );
+
+    expect(await service.getAppThemePreset(), AppThemePreset.fallback);
+
+    await service.setAppThemePreset(AppThemePreset.graphite);
+
+    expect(await service.getAppThemePreset(), AppThemePreset.graphite);
+  });
 }