fix issue and add consolidation

apps/edr-freight-api/src/modules/contracts/contract-booking.service.ts

@@ -2458,22 +2458,12 @@ export class ContractBookingService {
   private async assert20ftPairableAtCreate(
     dto: CreateBookingUnderContractDto,
   ): Promise<void> {
-    // Parity gate. 20ft containers ride two per wagon, so an odd total leaves
-    // one container that cannot be placed. Consolidation (pairing it with
-    // another customer's odd booking) is built end to end but switched off for
-    // now, so an odd total is rejected outright — server-side, because the
-    // frontend block alone is not a guarantee.
-    const ft20Quantity = (dto.containers ?? [])
-      .filter((line) => (line.containerSize ?? '').includes('20'))
-      .reduce((sum, line) => sum + Number(line.quantity || 0), 0);
-    if (ft20Quantity % 2 === 1) {
-      throw new BadRequestException(
-        `20ft containers travel two per wagon, so they must be booked in even ` +
-          `numbers. This booking has ${ft20Quantity} — add one more or remove ` +
-          `one (book ${ft20Quantity + 1} or ${ft20Quantity - 1}).`,
-      );
-    }
-
+    // Odd 20ft totals are no longer rejected here: the wagon consolidation gate
+    // that runs right after (consolidateDrawdown / needsConsolidationFromBooking,
+    // same machinery the plain booking flow already uses live) auto-pairs an odd
+    // total with another customer's odd booking or parks it as
+    // PENDING_CONSOLIDATION until one appears. This assert now only checks that
+    // any 20ft containers actually present can be weight-paired on a wagon.
     const twentyFtUnits = (dto.containers ?? [])
       .filter((line) => (line.containerSize ?? '').includes('20'))
       .flatMap((line, lineIdx) =>