feat: add per-ton cargo loading limits and update related services

apps/edr-freight-api/src/modules/train-scheduling/booking-batch.service.ts

@@ -71,6 +71,7 @@ import {
   bookingCargoTons,
   bulkItemsFitFor,
   bulkItemWagonsRequired,
+  bulkTonsPerWagon,
   bookingGrossWeightTons,
   deriveTrainCapacityFromLocomotive,
   sizePartialOfferWagons,
@@ -4100,8 +4101,15 @@ export class BookingBatchService implements OnModuleInit {
 
     const capacityTons = this.dimsFor(booking, wagonDims).capacityTons;
     const cargoTons = bookingCargoTons(booking);
+    // PER_TON cargo may cap tons per wagon below the rating (sugar 50T on a 70T
+    // wagon), so divide by the cap where one is configured for this type.
+    const tonsPerWagon = bulkTonsPerWagon(
+      booking.cargoType,
+      booking.cargoType?.wagonTypes?.[0]?.id,
+      capacityTons,
+    );
     const byWeight =
-      cargoTons > 0 && capacityTons > 0 ? Math.ceil(cargoTons / capacityTons) : 0;
+      cargoTons > 0 && tonsPerWagon > 0 ? Math.ceil(cargoTons / tonsPerWagon) : 0;
 
     // Break-bulk (PER_ITEM): indivisible items can need more wagons than raw
     // tonnage suggests (floor items-per-wagon loses the fractional capacity).
@@ -4169,6 +4177,13 @@ export class BookingBatchService implements OnModuleInit {
       .filter((o) => o.wagonTypeId && (stockByTypeId.get(o.wagonTypeId) ?? 0) > 0)
       .map((o) => {
         const wagonTypeId = o.wagonTypeId as string;
+        // Each type sized on its OWN per-wagon tonnage cap, not just its rating
+        // — a type capped lower swallows less per wagon.
+        const tonsPerWagon = bulkTonsPerWagon(
+          booking.cargoType,
+          wagonTypeId,
+          o.dims.capacityTons,
+        );
         const wagonsIfAlone = Math.max(
           1,
           bulkItemWagonsRequired(
@@ -4176,8 +4191,8 @@ export class BookingBatchService implements OnModuleInit {
             o.dims.capacityTons,
             bulkItemsFitFor(booking.cargoType, wagonTypeId),
           ) ||
-            (o.dims.capacityTons > 0
-              ? Math.ceil(bookingCargoTons(booking) / o.dims.capacityTons)
+            (tonsPerWagon > 0
+              ? Math.ceil(bookingCargoTons(booking) / tonsPerWagon)
               : total),
         );
         return {