add script to seed freight contracts across flow variants

apps/edr-freight-api/src/modules/train-scheduling/dto/update-schedule-date.dto.ts

@@ -0,0 +1,16 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { IsISO8601 } from 'class-validator';
+
+/**
+ * Reschedule a train's departure date (staff action on the ops board). Only
+ * allowed before the booking window opens; the new date must still leave room
+ * for the booking lead window before departure.
+ */
+export class UpdateScheduleDateDto {
+  @ApiProperty({
+    example: '2026-07-20T05:00:00.000Z',
+    description: 'New scheduled departure date/time (ISO 8601)',
+  })
+  @IsISO8601()
+  scheduleDate!: string;
+}