add wagon allocation snapshot to train schedules

apps/edr-freight-web/backoffice/src/components/trainScheduling/BookingWindowSettingsModal.tsx

@@ -232,6 +232,15 @@ export default function BookingWindowSettingsModal({
         </Alert>
       ) : (
         <Stack gap="lg">
+          {!isExport ? (
+            <Alert variant="light" color="orange" icon={<Info size={16} />}>
+              These settings apply to every train on this route (same origin and
+              destination) departing the same day — they all share one booking
+              window, so it opens, moves to document review, opens for payment,
+              and closes at the same time for all of them.
+            </Alert>
+          ) : null}
+
           {isExport ? (
             <Alert variant="light" color="blue" icon={<Info size={16} />}>
               Export schedules use a single first-come-first-served window: it