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/common/booking-guards.ts

@@ -95,6 +95,24 @@ export const TrainSchedulingLoad = () =>
 export const TrainSchedulingUnload = () =>
   BookingStaff(FREIGHT_PERMS.trainScheduling.unload);
 
+/**
+ * Per-station loading/unloading time windows — the four buttons are four
+ * permissions so start and end can be granted to different people. The same
+ * endpoint that records a click also edits it (explicit `at`), so each
+ * permission covers editing its own timestamp too.
+ */
+export const TrainSchedulingLoadingStart = () =>
+  BookingStaff(FREIGHT_PERMS.trainScheduling.loadingStart);
+
+export const TrainSchedulingLoadingEnd = () =>
+  BookingStaff(FREIGHT_PERMS.trainScheduling.loadingEnd);
+
+export const TrainSchedulingUnloadingStart = () =>
+  BookingStaff(FREIGHT_PERMS.trainScheduling.unloadingStart);
+
+export const TrainSchedulingUnloadingEnd = () =>
+  BookingStaff(FREIGHT_PERMS.trainScheduling.unloadingEnd);
+
 export const TrainSchedulingCancel = () =>
   BookingStaff(FREIGHT_PERMS.trainScheduling.cancel);