Restructure omni services and add Chatwoot research snapshot

research/chatwoot/app/services/messages/send_email_notification_service.rb

@@ -0,0 +1,40 @@
+class Messages::SendEmailNotificationService
+  pattr_initialize [:message!]
+
+  def perform
+    return unless should_send_email_notification?
+
+    conversation = message.conversation
+    conversation_mail_key = format(::Redis::Alfred::CONVERSATION_MAILER_KEY, conversation_id: conversation.id)
+
+    # Atomically set redis key to prevent duplicate email workers. Keep the key alive longer than
+    # the worker delay (1 hour) so slow queues don't enqueue duplicate jobs, but let it expire if
+    # the worker never manages to clean up.
+    return unless Redis::Alfred.set(conversation_mail_key, message.id, nx: true, ex: 1.hour.to_i)
+
+    ConversationReplyEmailJob.set(wait: 2.minutes).perform_later(conversation.id, message.id)
+    message.account.increment_email_sent_count
+  end
+
+  private
+
+  def should_send_email_notification?
+    return false unless message.email_notifiable_message?
+    return false if message.conversation.contact.email.blank?
+    return false unless message.account.within_email_rate_limit?
+
+    email_reply_enabled?
+  end
+
+  def email_reply_enabled?
+    inbox = message.inbox
+    case inbox.channel.class.to_s
+    when 'Channel::WebWidget'
+      inbox.channel.continuity_via_email
+    when 'Channel::Api'
+      inbox.account.feature_enabled?('email_continuity_on_api_channel')
+    else
+      false
+    end
+  end
+end