chore: refactor and cleanup of system services

lib/utils/validator.dart

@@ -0,0 +1,12 @@
+import 'package:lunasea/vendor.dart';
+
+class LunaValidator {
+  const LunaValidator._();
+
+  bool email(String email) {
+    const regex = r"(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)";
+    return RegExp(regex).hasMatch(email);
+  }
+}
+
+final validatorProvider = Provider((_) => const LunaValidator._());