fix: Captain not responding to campaign conversations (#13489)

Co-authored-by: Aakash Bakhle <48802744+aakashb95@users.noreply.github.com>

enterprise/lib/captain/tools/handoff_tool.rb

@@ -42,6 +42,10 @@ class Captain::Tools::HandoffTool < Captain::Tools::BasePublicTool
   end
 
   def send_out_of_office_message_if_applicable(conversation)
+    # Campaign conversations should never receive OOO templates — the campaign itself
+    # serves as the initial outreach, and OOO would be confusing in that context.
+    return if conversation.campaign.present?
+
     ::MessageTemplates::Template::OutOfOffice.perform_if_applicable(conversation)
   end