fix: Exclude notifications for blocked contacts, except mentions (#10659)

- Prevents notifications from being created for conversations or actions
involving blocked contacts.
- The exception is the conversation_mention notification type, which
will still be created when applicable.

app/builders/notification_builder.rb

@@ -25,6 +25,8 @@ class NotificationBuilder
   def build_notification
     # Create conversation_creation notification only if user is subscribed to it
     return if notification_type == 'conversation_creation' && !user_subscribed_to_notification?
+    # skip notifications for blocked conversations except for user mentions
+    return if primary_actor.contact.blocked? && notification_type != 'conversation_mention'
 
     user.notifications.create!(
       notification_type: notification_type,