feat: SAML feedback changes [CW-5666] (#12511)

enterprise/app/controllers/api/v1/auth_controller.rb

@@ -44,6 +44,16 @@ class Api::V1::AuthController < Api::BaseController
   end
 
   def render_saml_error
-    render json: { error: I18n.t('auth.saml.authentication_failed') }, status: :unauthorized
+    redirect_to sso_login_page_url(error: 'saml-authentication-failed')
+  end
+
+  def sso_login_page_url(error: nil)
+    frontend_url = ENV.fetch('FRONTEND_URL', nil)
+    params = { error: error }.compact
+
+    query = params.to_query
+    query_fragment = query.present? ? "?#{query}" : ''
+
+    "#{frontend_url}/app/login/sso#{query_fragment}"
   end
 end

enterprise/app/services/enterprise/billing/handle_stripe_event_service.rb

@@ -22,7 +22,7 @@ class Enterprise::Billing::HandleStripeEventService
   BUSINESS_PLAN_FEATURES = %w[sla custom_roles].freeze
 
   # Additional features available only in the Enterprise plan
-  ENTERPRISE_PLAN_FEATURES = %w[audit_logs disable_branding].freeze
+  ENTERPRISE_PLAN_FEATURES = %w[audit_logs disable_branding saml].freeze
 
   def perform(event:)
     @event = event