feat(warehouse): Batch 7 — Import Arrive Queue (arrived import trains, read-only)

- SchedulingReadFacade: importArriveQueue() + importTrainDetail() — read-only SELECTs only,
  direction derived from origin/destination station countries (route-based), so EXPORT/DOMESTIC
  trains are excluded. Per-train booking/container/cargo counts.
- GET /warehouse-inventory/import/arrive-queue + /import/trains/:scheduleId/items
- Import tab restructured into sub-tabs: Arrive Queue (implemented) / Unloaded Queue /
  Dispatch Queue (placeholders for next batch)
- ImportArriveQueueTab: train table (schedule id, train #, route, origin, destination, arrival,
  bookings/containers/cargoes, status) with Open (expandable assigned-items detail) + Auto Unload
  (reuses existing per-booking unload endpoint over the train's bookings)
- Batch7TestDataSeeder: 1 arrived IMPORT train (SEED-IMP-001) + 1 arrived EXPORT train
  (SEED-EXP-001, proves exclusion); idempotent
- Train schedule service logic untouched (facade is SELECT-only)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/edr-freight-web/backoffice/src/constants/URLS.ts

@@ -317,6 +317,9 @@ export const URL_CONSTANTS = {
     READY_TO_LOAD_EXPORT: '/warehouse-inventory/ready-to-load-export',
     LOADED_EXPORT: '/warehouse-inventory/loaded-export',
     BULK_DISPATCH_EXPORT: '/warehouse-inventory/bulk-dispatch-export',
+    IMPORT_ARRIVE_QUEUE: '/warehouse-inventory/import/arrive-queue',
+    IMPORT_TRAIN_ITEMS: (scheduleId: string) =>
+      `/warehouse-inventory/import/trains/${scheduleId}/items`,
   },
 
   WAREHOUSE_LOADINGS: {