feat: ensure captain limits

config/locales/en.yml

@@ -231,6 +231,7 @@ en:
       description: 'Create issues in Linear directly from your conversation window. Alternatively, link existing Linear issues for a more streamlined and efficient issue tracking process.'
   captain:
     copilot_error: 'Please connect an assistant to this inbox to use copilot'
+    copilot_limit: 'You are out of copilot credits. You can buy more credits from the billing section.'
   public_portal:
     search:
       search_placeholder: Search for article by title or body...

enterprise/app/controllers/enterprise/api/v1/accounts/conversations_controller.rb

@@ -7,6 +7,7 @@ module Enterprise::Api::V1::Accounts::ConversationsController
   def copilot
     assistant = @conversation.inbox.captain_assistant
     return render json: { message: I18n.t('captain.copilot_error') } unless assistant
+    return render json: { message: I18n.t('captain.copilot_limit') } unless @conversation.inbox.captain_active?
 
     response = Captain::Copilot::ChatService.new(
       assistant,

enterprise/app/services/enterprise/message_templates/hook_execution_service.rb

@@ -10,6 +10,6 @@ module Enterprise::MessageTemplates::HookExecutionService
   end
 
   def should_process_captain_response?
-    conversation.pending? && message.incoming? && inbox.captain_assistant.present?
+    conversation.pending? && message.incoming? && inbox.captain_active?
   end
 end