Refactor wagon type handling and container wagon calculations

- Removed maxWagonsPerTrain from WagonType entity and related DTOs.
- Updated containerWagonsForLines function to calculate required wagons based on container lines more accurately.
- Added unit tests for containerWagonsForLines to ensure correct calculations.
- Adjusted related services and scripts to reflect the removal of maxWagonsPerTrain.
- Enhanced booking and contract components to use new status labels for better user experience.
- Implemented validation for unique container numbers in shipment forms.

apps/edr-freight-api/src/modules/train-scheduling/wagon-plan.util.ts

@@ -89,18 +89,38 @@ export function containersPerWagonFromType(wagonsPerUnit: number): number {
   return Math.max(1, Math.round(1 / wpu));
 }
 
-function lineWagonsRequired(line: {
+type ContainerLine = {
   quantity?: number | null;
   wagonsRequired?: number | null;
   containerType?: { wagonsPerUnit?: number | null; sizeFt?: number | null } | null;
-}): number {
+};
+
+/**
+ * RAW (un-ceiled) wagon fraction one container line occupies: qty × wagonsPerUnit
+ * (40ft = 1, 20ft = 0.5). Two 20ft = 1.0, three 20ft = 1.5. Kept fractional so
+ * the BOOKING total is ceiled once — ceiling per line over-counts a booking that
+ * splits its 20ft units across several lines (3×20 + 3×20 = 3 wagons, not 4).
+ */
+function lineWagonsRaw(line: ContainerLine): number {
   const qty = Number(line.quantity ?? 0);
   if (qty <= 0) return 0;
   const wpu = Number(line.containerType?.wagonsPerUnit);
   if (Number.isFinite(wpu) && wpu > 0) {
-    return Math.ceil(qty * wpu);
+    return qty * wpu;
   }
-  return Math.max(1, Math.ceil(Number(line.wagonsRequired ?? 1)));
+  // No wagonsPerUnit on the type: fall back to the line's stored fraction, else
+  // treat the whole line as one wagon.
+  const stored = Number(line.wagonsRequired);
+  return Number.isFinite(stored) && stored > 0 ? stored : 1;
+}
+
+/**
+ * Whole wagons a set of container lines needs: ceil the summed RAW fraction so a
+ * half-full 20ft wagon rounds up ONCE at the booking level. Empty set → 0.
+ */
+export function containerWagonsForLines(lines: ContainerLine[]): number {
+  const raw = lines.reduce((sum, line) => sum + lineWagonsRaw(line), 0);
+  return raw > 0 ? Math.ceil(raw) : 0;
 }
 
 /**
@@ -110,15 +130,16 @@ export function buildContainerWagonPlan(
   bookings: Booking[],
   wagonType: WagonType,
 ): WagonPlanSlot[] {
+  // Whole wagons PER BOOKING (ceil each booking's total TEU once — a 20ft unit
+  // can share a wagon with another 20ft of the SAME booking, never across
+  // bookings), then sum. Ceiling per line instead would over-count a booking
+  // that splits its 20ft units across several lines.
   const totalSlots = bookings.reduce((sum, booking) => {
-    const lineSlots = (booking.bookingContainers ?? []).reduce(
-      (lineSum, line) => lineSum + lineWagonsRequired(line),
-      0,
-    );
-    return sum + Math.max(lineSlots, 1);
+    const bookingSlots = containerWagonsForLines(booking.bookingContainers ?? []);
+    return sum + Math.max(bookingSlots, 1);
   }, 0);
 
-  const slots = Math.max(1, Math.ceil(totalSlots));
+  const slots = Math.max(1, totalSlots);
   const basePlan: WagonPlanSlot[] = Array.from({ length: slots }, (_, index) => ({
     sequenceNo: index + 1,
     wagonTypeId: wagonType.id,
@@ -424,7 +445,7 @@ export function validateBulkWagonSlotWeights(wagonPlan: WagonPlanSlot[]): string
 
 export function validateTrainLimits(
   wagonPlan: WagonPlanSlot[],
-  wagonType: WagonType,
+  wagonType: Pick<WagonType, 'lengthMeters'>,
   limits?: TrainLimitConfig,
 ): string[] {
   const violations: string[] = [];
@@ -478,7 +499,7 @@ export function validateMixedTrainLimits(
 
   return validateTrainLimits(
     wagonPlan,
-    { maxWagonsPerTrain } as WagonType,
+    { lengthMeters: minWagonLength },
     { ...limits, maxWagonsPerTrain },
   );
 }