feat: enhance train scheduling and contract management features

- Added StationWorkControls to manage loading/unloading phases in TrainScheduleV2DetailPage.
- Implemented API endpoints for recording station work and managing wagon detach requests.
- Updated contract templates to include Ethiopian customs handling options.
- Enhanced shipment forms to collect customs clearing agent details for without-customs bookings.
- Introduced NUMBER_OF_WAGONS as a unit of measure for bulk cargo, allowing customers to specify wagon counts.
- Improved validation for customs clearing agent information in shipment forms.
- Updated various components and services to accommodate new features and ensure data integrity.

apps/edr-freight-api/src/modules/train-scheduling/dto/station-work.dto.ts

@@ -0,0 +1,14 @@
+import { ApiPropertyOptional } from '@nestjs/swagger';
+import { IsISO8601, IsOptional } from 'class-validator';
+
+/**
+ * A station loading/unloading window click. `at` omitted = "now" (the button
+ * click); `at` given = record or correct the timestamp after the fact — same
+ * endpoint, same permission.
+ */
+export class StationWorkDto {
+  @ApiPropertyOptional({ description: 'ISO timestamp; omitted = now. Never in the future.' })
+  @IsOptional()
+  @IsISO8601()
+  at?: string;
+}