fix: add missing enum member for pendingSignInEmail in StorageKey

Author: fulleni

lib/src/storage_keys.dart

@@ -15,7 +15,11 @@ enum StorageKey {
 
   /// Key for storing a boolean flag indicating whether the user has completed
   /// the onboarding flow.
-  hasSeenOnboarding;
+  hasSeenOnboarding,
+  
+  /// Key for storing the email address of a user who is in the process of 
+  /// signing in, useful for pre-filling the email field.
+  pendingSignInEmail;
 
   /// Returns the snake_case string representation of the key for storage.
   String get stringValue {
@@ -24,6 +28,8 @@ enum StorageKey {
         return 'auth_token';
       case StorageKey.hasSeenOnboarding:
         return 'has_seen_onboarding';
+      case StorageKey.pendingSignInEmail:
+        return 'pending_sign_in_email';
     }
   }
 }