feat: enhance booking cancellation logic for consolidated pairs with one paid side

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

@@ -3991,9 +3991,10 @@ export class BookingBatchService implements OnModuleInit {
    * taken, so it boards, even when the webhook arrived after the deadline or the
    * settle read a stale row. It allocates onto the train it was selected for; if
    * the wagon planner then finds no physical wagon, the booking stays linked and
-   * staff assign wagons manually. Consolidated bookings are exempt from the
-   * rescue: the shared wagon is both-or-neither, and settleReserved owns that
-   * pair decision.
+   * staff assign wagons manually. EXCEPTION — a consolidated booking whose
+   * partner lapsed unpaid is NOT rescued: its odd 20ft cannot board without the
+   * partner, so the paid side is cancelled with the cancellation fee (the
+   * partnerLapsed listener in BookingWagonCancellationService).
    */
   private async expire(
     booking: Booking,
@@ -4001,10 +4002,11 @@ export class BookingBatchService implements OnModuleInit {
   ): Promise<void> {
     // Consolidated pair: break the link FIRST, then settle each side singly.
     //  - neither paid  → both expire, no fee.
-    //  - one side paid → the paid half keeps the whole wagon (rescued by the
-    //    paid guard below at no extra cost); the lapsed half expires and owes
-    //    the cancellation fee (the 'partnerLapsed' event opens the fee invoice
-    //    in BookingWagonCancellationService).
+    //  - one side paid → BOTH die: the unpaid half expires fee-free (fees only
+    //    apply to paid bookings); the paid half cannot board alone, so the
+    //    'partnerLapsed' event cancels it with the cancellation fee on ceil of
+    //    its wagons (BookingWagonCancellationService) — paid freight kept as
+    //    rebooking credit for GL staff.
     //  - both paid     → nothing to expire; the paid guard rescues.
     if (booking.consolidationPartnerId) {
       const partnerId = booking.consolidationPartnerId;
@@ -4029,19 +4031,22 @@ export class BookingBatchService implements OnModuleInit {
       if (partnerRow) partnerRow.consolidationPartnerId = null;
 
       if (selfPaid && !partnerPaid) {
-        // Wrong side called first: the lapsed partner is the one that expires
-        // (with its fee); this paid booking falls through to the rescue below.
+        // Wrong side called first: the unpaid partner expires fee-free; this
+        // PAID booking cannot board without it, so the listener cancels it
+        // with the cancellation fee — never rescued.
         if (partnerRow && !["EXPIRED", "CANCELLED"].includes(partnerRow.status)) {
-          this.eventEmitter?.emit("booking.consolidation.partnerLapsed", {
-            expiredBookingId: partnerRow.id,
-          });
           await this.expire(partnerRow, reason);
         }
-      } else if (!selfPaid && partnerPaid) {
         this.eventEmitter?.emit("booking.consolidation.partnerLapsed", {
-          expiredBookingId: booking.id,
+          paidBookingId: booking.id,
+        });
+        return;
+      } else if (!selfPaid && partnerPaid) {
+        // This unpaid side expires below, fee-free; the PAID partner cannot
+        // board alone, so the listener cancels it with the cancellation fee.
+        this.eventEmitter?.emit("booking.consolidation.partnerLapsed", {
+          paidBookingId: partnerId,
         });
-        // fall through: this side expires below; the paid partner is untouched.
       } else if (!selfPaid && !partnerPaid) {
         if (partnerRow && !["EXPIRED", "CANCELLED"].includes(partnerRow.status)) {
           await this.expire(partnerRow, reason);
@@ -4335,8 +4340,8 @@ export class BookingBatchService implements OnModuleInit {
       swept.add(booking.id);
       // Consolidated pair: the partner may sit outside this route-day's result
       // set (different yards/day/status), so cascade explicitly — an unpaid
-      // partner expires with this booking; a PAID partner keeps the whole
-      // wagon and this booking owes the cancellation fee (partnerLapsed).
+      // partner expires with this booking, fee-free; a PAID partner cannot
+      // board alone, so partnerLapsed cancels it with the cancellation fee.
       if (booking.consolidationPartnerId) {
         const partner = await this.dataSource.getRepository(Booking).findOne({
           where: { id: booking.consolidationPartnerId },
@@ -4352,7 +4357,7 @@ export class BookingBatchService implements OnModuleInit {
             partner.paymentStatus === "PAID" || partner.status === "PAID";
           if (partnerPaid) {
             this.eventEmitter?.emit("booking.consolidation.partnerLapsed", {
-              expiredBookingId: booking.id,
+              paidBookingId: partner.id,
             });
           } else if (!["EXPIRED", "CANCELLED"].includes(partner.status)) {
             swept.add(partner.id);