feat(warehouse): Batch 8 — Import Auto Unload Arrived Bookings (→ UNLOADED)

- New UNLOADED inventory status (train-arrival landing state) + transitions + unloaded_at column
  (idempotent migration 1791000000003) + INVENTORY_UNLOADED activity type
- POST /warehouse-inventory/import/auto-unload-arrived-bookings { scheduleId }: validates ARRIVED
  IMPORT train, unloads all eligible assigned bookings (IN_TRANSIT/ARRIVED_AT_*) into UNLOADED,
  records unloadedAt + activity. Does NOT store and does NOT inspect. Reuses allocation + inventory
  plumbing. Returns { unloadedCount, skippedCount, failedCount, results }.
- Arrive Queue "Auto Unload Arrived Bookings" button now calls the new endpoint (was per-booking loop)
- Import → Unloaded Queue tab: lists UNLOADED items via InventoryWorkbench (existing actions preserved:
  Inspect/Store/Move/History) + a Last Mile action shown ONLY when booking requested door delivery
- Batch8TestDataSeeder: sets seed import train bookings to IN_TRANSIT (unload-eligible)
- Verified: auto-unload → 1 UNLOADED (unloadedAt set, not stored, not inspected); ineligible skipped;
  idempotent re-run skips already-unloaded

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

apps/edr-freight-api/src/migrations/1791000000003-AddInventoryUnloadedAt.ts

@@ -0,0 +1,27 @@
+import { MigrationInterface, QueryRunner, TableColumn } from 'typeorm';
+
+/**
+ * Batch 8 — train-arrival unload landing state on warehouse_inventory:
+ *  - unloaded_at: when the goods were unloaded off the arrived train (before storage/inspection)
+ *
+ * The `status` column is a free varchar, so the new 'UNLOADED' value needs no schema change.
+ * Idempotent: the shared dev DB may already carry this column (added by another checkout).
+ */
+export class AddInventoryUnloadedAt1791000000003 implements MigrationInterface {
+  private readonly table = 'freight.warehouse_inventory';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    if (!(await queryRunner.hasColumn(this.table, 'unloaded_at'))) {
+      await queryRunner.addColumn(
+        this.table,
+        new TableColumn({ name: 'unloaded_at', type: 'timestamptz', isNullable: true }),
+      );
+    }
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    if (await queryRunner.hasColumn(this.table, 'unloaded_at')) {
+      await queryRunner.dropColumn(this.table, 'unloaded_at');
+    }
+  }
+}