refactor: remove unused auth & verification services

- Removed `SimpleAuthTokenService`.
- Removed `InMemoryVerificationCodeStorageService`.

Author: fulleni

lib/src/services/simple_auth_token_service.dart

@@ -67,118 +67,3 @@ abstract class VerificationCodeStorageService {
   /// Disposes of any resources used by the service (e.g., timers for cleanup).
   void dispose();
 }
-
-/// {@template in_memory_verification_code_storage_service}
-/// An in-memory implementation of [VerificationCodeStorageService].
-///
-/// Stores verification codes in memory. Not suitable for production if
-/// persistence across server restarts is required.
-/// {@endtemplate}
-class InMemoryVerificationCodeStorageService
-    implements VerificationCodeStorageService {
-  /// {@macro in_memory_verification_code_storage_service}
-  InMemoryVerificationCodeStorageService({
-    Duration cleanupInterval = _defaultCleanupInterval,
-    this.codeExpiryDuration = _defaultCodeExpiryDuration,
-  }) {
-    _cleanupTimer = Timer.periodic(cleanupInterval, (_) async {
-      try {
-        await cleanupExpiredCodes();
-      } catch (e) {
-        print(
-          '[InMemoryVerificationCodeStorageService] Error during scheduled cleanup: $e',
-        );
-      }
-    });
-    print(
-      '[InMemoryVerificationCodeStorageService] Initialized with cleanup interval: '
-      '$cleanupInterval and code expiry: $codeExpiryDuration',
-    );
-  }
-
-  /// Duration for which generated codes are considered valid.
-  final Duration codeExpiryDuration;
-
-  /// Store for standard sign-in codes: Key is email.
-  @visibleForTesting
-  final Map<String, _SignInCodeEntry> signInCodesStore = {};
-
-  Timer? _cleanupTimer;
-  bool _isDisposed = false;
-  final Random _random = Random();
-
-  String _generateNumericCode({int length = 6}) {
-    final buffer = StringBuffer();
-    for (var i = 0; i < length; i++) {
-      buffer.write(_random.nextInt(10).toString());
-    }
-    return buffer.toString();
-  }
-
-  @override
-  Future<String> generateAndStoreSignInCode(String email) async {
-    if (_isDisposed) {
-      throw const OperationFailedException('Service is disposed.');
-    }
-    await Future<void>.delayed(Duration.zero); // Simulate async
-    final code = _generateNumericCode();
-    final expiresAt = DateTime.now().add(codeExpiryDuration);
-    signInCodesStore[email] = _SignInCodeEntry(code, expiresAt);
-    print(
-      '[InMemoryVerificationCodeStorageService] Stored sign-in code: $code for $email (expires: $expiresAt)',
-    );
-    return code;
-  }
-
-  @override
-  Future<bool> validateSignInCode(String email, String code) async {
-    if (_isDisposed) return false;
-    await Future<void>.delayed(Duration.zero); // Simulate async
-    final entry = signInCodesStore[email];
-    if (entry == null || entry.isExpired || entry.code != code) {
-      return false;
-    }
-    return true;
-  }
-
-  @override
-  Future<void> clearSignInCode(String email) async {
-    if (_isDisposed) return;
-    await Future<void>.delayed(Duration.zero); // Simulate async
-    signInCodesStore.remove(email);
-    print(
-      '[InMemoryVerificationCodeStorageService] Cleared sign-in code for $email',
-    );
-  }
-
-  @override
-  Future<void> cleanupExpiredCodes() async {
-    if (_isDisposed) return;
-    await Future<void>.delayed(Duration.zero); // Simulate async
-    var cleanedCount = 0;
-
-    signInCodesStore.removeWhere((key, entry) {
-      if (entry.isExpired) {
-        cleanedCount++;
-        return true;
-      }
-      return false;
-    });
-
-    if (cleanedCount > 0) {
-      print(
-        '[InMemoryVerificationCodeStorageService] Cleaned up $cleanedCount expired codes.',
-      );
-    }
-  }
-
-  @override
-  void dispose() {
-    if (!_isDisposed) {
-      _isDisposed = true;
-      _cleanupTimer?.cancel();
-      signInCodesStore.clear();
-      print('[InMemoryVerificationCodeStorageService] Disposed.');
-    }
-  }
-}