feat(dependencies): add rxdart package and improve string extension methods for better handling of empty strings and gender parsing

test/features/registration_v2/models/registration_model_test.dart

@@ -0,0 +1,28 @@
+import 'package:eatvio_app/features/registration_v2/models/registration_model.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('RegistrationModel', () {
+    test('создает RegistrationModel с правильными значениями', () {
+      final model = RegistrationModel(
+        firstName: 'John',
+        lastName: 'Doe',
+        email: 'john@example.com',
+        phone: '+79001234567',
+        gender: 'male',
+        password: 'password123',
+        confirmPassword: 'password123',
+        weight: 70,
+        height: 175,
+        activityCoefficient: 1.5,
+        birthday: '1990-01-01',
+      );
+
+      expect(model.firstName, 'John');
+      expect(model.email, 'john@example.com');
+      expect(model.weight, 70);
+      expect(model.height, 175);
+    });
+  });
+}
+