feat: Implement handling for partially loaded bookings in train scheduling

- Added  to manage decisions on partially loaded bookings during log-pass and dispatch actions.
- Enhanced  to track and manage bookings left behind when a train departs a yard.
- Updated  and  to pass necessary station data for handling partially loaded bookings.
- Modified  and  to account for customer-fault fees and ensure proper handling of credits.
- Introduced fault tracking in  interface to differentiate between customer and EDR faults.

apps/edr-freight-api/src/modules/bookings/booking-wagon-cancellation.service.spec.ts

@@ -232,3 +232,91 @@ describe('BookingWagonCancellationService.buildRebookDto (bulk wagon count)', ()
     expect(dto.requestedWagons).toBeUndefined();
   });
 });
+
+/**
+ * The cancellation fee is paid BEFORE the credit is redeemed.
+ *
+ * An at-loading cut applies immediately and opens the credit while its fee
+ * invoice stays open, so CREDIT_AVAILABLE on its own never means the fee was
+ * settled. Without the gate the customer rebooks the same wagons and the
+ * cancellation fee is simply never collected. EDR-fault cuts carry no fee and
+ * must stay freely rebookable — partial or whole, container or bulk.
+ */
+describe('BookingWagonCancellationService.rebook (cancellation fee gate)', () => {
+  const source = {
+    id: 'b1',
+    contractId: 'c1',
+    paymentCurrency: 'ETB',
+    originYardId: 'y1',
+    destinationYardId: 'y2',
+    tradeDirection: 'IMPORT',
+  };
+
+  const makeSvc = (row: Record<string, unknown>) => {
+    const svc = Object.create(BookingWagonCancellationService.prototype) as Record<
+      string,
+      unknown
+    > & { rebook(id: string, dto: unknown): Promise<unknown> };
+    svc.repo = { findById: async () => row };
+    svc.bookingsRepository = {
+      findById: async () => source,
+      findByIdWithFiles: async () => null,
+    };
+    return svc;
+  };
+
+  /** Bulk credit — no bySize, so nothing depends on container snapshots. */
+  const bulkRow = (over: Record<string, unknown>) => ({
+    id: 'wc1',
+    bookingId: 'b1',
+    status: 'CREDIT_AVAILABLE',
+    creditAmount: 5000,
+    wagonsCancelled: 2,
+    cancelledQuantities: { bulkTons: 100 },
+    feeCurrency: 'ETB',
+    ...over,
+  });
+
+  it('blocks a rebook while a customer-fault fee is unpaid', async () => {
+    const svc = makeSvc(
+      bulkRow({ fault: 'CUSTOMER', feeAmount: 1500, feePaidAt: null }),
+    );
+    await expect(svc.rebook('wc1', { scheduledDate: '2026-09-01' })).rejects.toThrow(
+      /pay the ETB 1500\.00 cancellation fee for 2 wagon\(s\)/i,
+    );
+  });
+
+  it('blocks a WHOLE-booking customer-fault cancel just the same', async () => {
+    const svc = makeSvc(
+      bulkRow({ fault: 'CUSTOMER', feeAmount: 4000, feePaidAt: null, wagonsCancelled: 4 }),
+    );
+    await expect(svc.rebook('wc1', { scheduledDate: '2026-09-01' })).rejects.toThrow(
+      /4 wagon\(s\) before rebooking/i,
+    );
+  });
+
+  it('lets the rebook through once the fee is paid', async () => {
+    const svc = makeSvc(
+      bulkRow({ fault: 'CUSTOMER', feeAmount: 1500, feePaidAt: new Date() }),
+    );
+    // Past the gate it fails later (no contract/create wiring in this harness) —
+    // what matters is that it is no longer the fee that stops it.
+    await expect(
+      svc.rebook('wc1', { scheduledDate: '2026-09-01' }),
+    ).rejects.not.toThrow(/cancellation fee/i);
+  });
+
+  it('never charges an EDR-fault cut', async () => {
+    const svc = makeSvc(bulkRow({ fault: 'EDR', feeAmount: 0, feePaidAt: null }));
+    await expect(
+      svc.rebook('wc1', { scheduledDate: '2026-09-01' }),
+    ).rejects.not.toThrow(/cancellation fee/i);
+  });
+
+  it('leaves legacy rows without a fee untouched', async () => {
+    const svc = makeSvc(bulkRow({ fault: null, feeAmount: 0, feePaidAt: null }));
+    await expect(
+      svc.rebook('wc1', { scheduledDate: '2026-09-01' }),
+    ).rejects.not.toThrow(/cancellation fee/i);
+  });
+});

apps/edr-freight-api/src/modules/bookings/booking-wagon-cancellation.service.ts

@@ -1003,6 +1003,18 @@ export class BookingWagonCancellationService {
         'This cancellation has no rebooking credit — the booking was never paid. Create a new booking instead.',
       );
     }
+    // Customer-fault fee settles BEFORE the credit is redeemed. An at-loading
+    // cut applies immediately and opens the credit while its invoice stays
+    // open, so CREDIT_AVAILABLE alone does not mean the fee was paid — without
+    // this the customer rebooks the wagons and never pays the cancellation
+    // fee the notice already promised. EDR fault carries no fee and is
+    // unaffected; onFeePaid stamps feePaidAt and the gate opens by itself.
+    if (row.fault === 'CUSTOMER' && Number(row.feeAmount) > 0 && !row.feePaidAt) {
+      throw new BadRequestException(
+        `Pay the ${row.feeCurrency} ${Number(row.feeAmount).toFixed(2)} cancellation fee for ` +
+          `${Math.ceil(Number(row.wagonsCancelled))} wagon(s) before rebooking this credit.`,
+      );
+    }
     const source = await this.bookingsRepository.findById(row.bookingId);
     if (!source) throw new NotFoundException(`Booking ${row.bookingId} not found.`);
     if (!source.contractId) {

apps/edr-freight-api/src/modules/train-scheduling/checkpoint-leave-behind.spec.ts

@@ -0,0 +1,268 @@
+import { BadRequestException } from "@nestjs/common";
+
+import { TrainSchedulingService } from "./services/train-scheduling.service";
+
+/**
+ * Mid-corridor leave-behind. Logging a pass at station N means the train has
+ * LEFT station N-1, so cargo that boarded back there has had its last chance
+ * to load: anything the operator did not tick rides no further and is
+ * unassigned back to the booking pool.
+ *
+ * Dispatch already does this for the origin yard; these cover the log-pass
+ * twin, plus the structured payload the UI needs to offer the
+ * EDR-fault / customer-fault cut on a part-loaded booking.
+ */
+describe("recordCheckpoint — mid-corridor leave-behind", () => {
+  const STATIONS = [
+    { sequenceNo: 0, yardId: "yard-a", label: "Yard A" },
+    { sequenceNo: 1, yardId: "yard-b", label: "Yard B" },
+    { sequenceNo: 2, yardId: "yard-c", label: "Yard C" },
+  ];
+
+  /**
+   * Exercises the leave-behind block in isolation — the surrounding
+   * recordCheckpoint does heavy graph/transaction work irrelevant here.
+   */
+  const runLeaveBehind = async (
+    dto: { sequenceNo: number; loadedBookingIds?: string[] },
+    candidatesByYard: Record<string, string[]>,
+  ) => {
+    const unassigned: Array<{ scheduleId: string; bookingId: string }> = [];
+    const svc = Object.create(TrainSchedulingService.prototype) as {
+      unloadedBoarderIdsAtYard(
+        scheduleId: string,
+        yardId: string,
+      ): Promise<string[]>;
+      unassignBooking(
+        scheduleId: string,
+        bookingId: string,
+        userId?: string,
+      ): Promise<void>;
+    };
+    svc.unloadedBoarderIdsAtYard = async (
+      _scheduleId: string,
+      yardId: string,
+    ) => candidatesByYard[yardId] ?? [];
+    svc.unassignBooking = async (scheduleId: string, bookingId: string) => {
+      unassigned.push({ scheduleId, bookingId });
+    };
+
+    // Mirrors the block inside recordCheckpoint.
+    if (dto.loadedBookingIds && dto.sequenceNo > 0) {
+      const departedYardId = STATIONS.find(
+        (s) => s.sequenceNo === dto.sequenceNo - 1,
+      )?.yardId;
+      if (departedYardId) {
+        const keep = new Set(dto.loadedBookingIds);
+        const candidates = await svc.unloadedBoarderIdsAtYard(
+          "sched-1",
+          departedYardId,
+        );
+        for (const bookingId of candidates.filter((id) => !keep.has(id))) {
+          await svc.unassignBooking("sched-1", bookingId, undefined);
+        }
+      }
+    }
+    return unassigned.map((u) => u.bookingId);
+  };
+
+  it("drops the unticked boarders of the yard the train just left", async () => {
+    // b4 and b5 boarded at Yard B; only b5 was loaded. Logging Yard C means
+    // the train has left B, so b4 is stranded and comes off the train.
+    const dropped = await runLeaveBehind(
+      { sequenceNo: 2, loadedBookingIds: ["b5"] },
+      { "yard-b": ["b4", "b5"] },
+    );
+    expect(dropped).toEqual(["b4"]);
+  });
+
+  it("scopes the drop to the DEPARTED yard, never the one being logged", async () => {
+    // Cargo boarding at Yard C is not due until the train is there — logging
+    // the pass at C must not shed it.
+    const dropped = await runLeaveBehind(
+      { sequenceNo: 2, loadedBookingIds: [] },
+      { "yard-b": [], "yard-c": ["b6", "b7"] },
+    );
+    expect(dropped).toEqual([]);
+  });
+
+  it("leaves nobody behind when the client omits the list", async () => {
+    // Older clients send no list — the historic behavior is that everyone rides.
+    const dropped = await runLeaveBehind(
+      { sequenceNo: 2 },
+      { "yard-b": ["b4"] },
+    );
+    expect(dropped).toEqual([]);
+  });
+
+  it("does not shed at the origin — that is dispatch's decision", async () => {
+    const dropped = await runLeaveBehind(
+      { sequenceNo: 0, loadedBookingIds: [] },
+      { "yard-a": ["b1", "b3"] },
+    );
+    expect(dropped).toEqual([]);
+  });
+
+  it("keeps every ticked booking on the train", async () => {
+    const dropped = await runLeaveBehind(
+      { sequenceNo: 2, loadedBookingIds: ["b4", "b5"] },
+      { "yard-b": ["b4", "b5"] },
+    );
+    expect(dropped).toEqual([]);
+  });
+});
+
+describe("assertNoPartiallyLoadedBookings — structured payload", () => {
+  const makeService = (
+    rows: Array<{
+      bookingId: string;
+      reference: string;
+      loaded: string;
+      total: string;
+      unloadedAllocationIds: string[];
+    }>,
+  ) => {
+    const svc = Object.create(TrainSchedulingService.prototype) as {
+      dataSource: {
+        query: (sql: string, params: unknown[]) => Promise<unknown>;
+      };
+      assertNoPartiallyLoadedBookings(
+        schedule: unknown,
+        boardingYardId: string,
+        context: { action: string; yardLabel?: string },
+      ): Promise<void>;
+    };
+    svc.dataSource = { query: async () => rows };
+    return svc;
+  };
+  const schedule = {
+    id: "sched-1",
+    trainSetId: "set-1",
+    originStationId: "yard-a",
+  };
+
+  it("carries the never-loaded allocation ids the fault-cut modal needs", async () => {
+    const svc = makeService([
+      {
+        bookingId: "b4",
+        reference: "BK-2026-000853",
+        loaded: "1",
+        total: "4",
+        unloadedAllocationIds: ["w2", "w3", "w4"],
+      },
+    ]);
+
+    const err = await svc
+      .assertNoPartiallyLoadedBookings(schedule, "yard-b", {
+        action: "record this checkpoint",
+        yardLabel: "Yard B",
+      })
+      .catch((e: unknown) => e);
+
+    expect(err).toBeInstanceOf(BadRequestException);
+    const body = (err as BadRequestException).getResponse() as {
+      code: string;
+      message: string;
+      partiallyLoaded: {
+        yardLabel: string | null;
+        bookings: Array<{
+          bookingId: string;
+          loadedWagons: number;
+          totalWagons: number;
+          unloadedAllocationIds: string[];
+        }>;
+      };
+    };
+
+    expect(body.code).toBe("PARTIALLY_LOADED_BOOKINGS");
+    expect(body.partiallyLoaded.yardLabel).toBe("Yard B");
+    expect(body.partiallyLoaded.bookings).toEqual([
+      {
+        bookingId: "b4",
+        reference: "BK-2026-000853",
+        loadedWagons: 1,
+        totalWagons: 4,
+        unloadedAllocationIds: ["w2", "w3", "w4"],
+      },
+    ]);
+    // The prose message survives for logs and older clients.
+    expect(body.message).toContain("BK-2026-000853 (1/4 wagons loaded)");
+  });
+
+  it("stays silent when nothing at the yard is half-loaded", async () => {
+    const svc = makeService([]);
+    await expect(
+      svc.assertNoPartiallyLoadedBookings(schedule, "yard-b", {
+        action: "dispatch",
+      }),
+    ).resolves.toBeUndefined();
+  });
+});
+
+/**
+ * Dispatch's origin auto-load. This UPDATE is the reason an unticked booking
+ * could still end up marked loaded: it stamps every PAID origin boarder, so
+ * without the confirmed-list guard a booking left attached (or one the
+ * unassign predicate cannot shed) rides as if its cargo were aboard.
+ */
+describe('dispatchSchedule — origin auto-load respects the confirmed list', () => {
+  /** Mirrors the `($4::uuid[] IS NULL OR b.id = ANY($4::uuid[]))` guard. */
+  const wouldAutoLoad = (bookingId: string, confirmed: string[] | undefined) =>
+    confirmed === undefined || confirmed.includes(bookingId);
+
+  it('stamps only the ticked bookings', () => {
+    expect(wouldAutoLoad('b2', ['b2'])).toBe(true);
+    expect(wouldAutoLoad('b1', ['b2'])).toBe(false);
+  });
+
+  it('stamps nobody when the operator unticks everyone', () => {
+    expect(wouldAutoLoad('b1', [])).toBe(false);
+  });
+
+  it('keeps the historic auto-load for clients that send no list', () => {
+    expect(wouldAutoLoad('b1', undefined)).toBe(true);
+    expect(wouldAutoLoad('b2', undefined)).toBe(true);
+  });
+});
+
+/**
+ * Empty wagons must travel with their train.
+ *
+ * The checkpoint position fix moves wagons by `current_train_schedule_id`, but
+ * dispatch used to bind only the PINNED slots (the ones carrying cargo). A
+ * built train rolls with its whole consist, so every empty wagon coupled to it
+ * was left unbound — and stayed recorded at the origin yard while the train it
+ * is hooked to travelled the corridor.
+ */
+describe('dispatchSchedule — the whole consist travels, not just loaded slots', () => {
+  /** Mirrors dispatch's binding set: pinned slots ∪ built-train consist. */
+  const boundAtDispatch = (
+    pinnedSlotWagonIds: Array<string | null>,
+    builtTrainWagonIds: string[],
+  ) => [
+    ...new Set([
+      ...pinnedSlotWagonIds.filter((id): id is string => Boolean(id)),
+      ...builtTrainWagonIds,
+    ]),
+  ];
+
+  it('binds the empty wagons coupled to the built train', () => {
+    // The real shape of the reported schedule: 3 slots carry cargo, 45 empties
+    // ride along. All 48 must move when a checkpoint is logged.
+    const pinned = ['w1', 'w2', 'w3'];
+    const consist = ['w1', 'w2', 'w3', 'e1', 'e2', 'e3'];
+    const bound = boundAtDispatch(pinned, consist);
+    expect(bound).toEqual(['w1', 'w2', 'w3', 'e1', 'e2', 'e3']);
+    expect(bound).toContain('e1');
+  });
+
+  it('never double-binds a wagon that is both pinned and on the train', () => {
+    const bound = boundAtDispatch(['w1', 'w1'], ['w1']);
+    expect(bound).toEqual(['w1']);
+  });
+
+  it('still binds pinned slots when there is no built train', () => {
+    // A set-only schedule (no Train row) has no consist to add.
+    expect(boundAtDispatch(['w1', null, 'w2'], [])).toEqual(['w1', 'w2']);
+  });
+});

apps/edr-freight-api/src/modules/train-scheduling/dto/record-checkpoint.dto.ts

@@ -1,5 +1,5 @@
-import { ApiProperty } from '@nestjs/swagger';
-import { TrainCheckpointKind } from '@edr/types';
+import { ApiProperty } from "@nestjs/swagger";
+import { TrainCheckpointKind } from "@edr/types";
 import {
   IsArray,
   IsEnum,
@@ -10,10 +10,12 @@ import {
   IsUUID,
   MaxLength,
   Min,
-} from 'class-validator';
+} from "class-validator";
 
 export class RecordCheckpointDto {
-  @ApiProperty({ description: 'Station position along the route (0 = origin).' })
+  @ApiProperty({
+    description: "Station position along the route (0 = origin).",
+  })
   @IsInt()
   @Min(0)
   sequenceNo!: number;
@@ -31,7 +33,7 @@ export class RecordCheckpointDto {
   @ApiProperty({
     required: false,
     description:
-      'ISO timestamp; defaults to now. Past allowed, future rejected, must be in corridor order.',
+      "ISO timestamp; defaults to now. Past allowed, future rejected, must be in corridor order.",
   })
   @IsOptional()
   @IsISO8601()
@@ -42,7 +44,10 @@ export class RecordCheckpointDto {
    * loading and unloading time. All optional: a stop logged without them still
    * records its staying time.
    */
-  @ApiProperty({ required: false, description: 'ISO timestamp; unloading start.' })
+  @ApiProperty({
+    required: false,
+    description: "ISO timestamp; unloading start.",
+  })
   @IsOptional()
   @IsISO8601()
   unloadingStartedAt?: string;
@@ -62,6 +67,24 @@ export class RecordCheckpointDto {
   @IsISO8601()
   loadingCompletedAt?: string;
 
+  /**
+   * Mid-corridor leave-behind, the log-pass twin of DispatchScheduleDto's field.
+   * Recording THIS station means the train left the previous one, so the
+   * bookings that boarded back there have had their last chance to load. When
+   * present, only these ride on; every other unloaded boarder of the departed
+   * yard is deallocated from its wagon and returned to the booking pool.
+   * Absent (older clients) = nobody is left behind, the historic behavior.
+   */
+  @ApiProperty({
+    required: false,
+    description:
+      "Bookings from the yard just departed confirmed loaded; the rest are unassigned back to the pool. Omit to leave nobody behind.",
+  })
+  @IsOptional()
+  @IsArray()
+  @IsUUID("4", { each: true })
+  loadedBookingIds?: string[];
+
   @ApiProperty({ required: false })
   @IsOptional()
   @IsString()
@@ -73,7 +96,8 @@ export class RecordCheckpointDto {
 export class UpdateCheckpointDto {
   @ApiProperty({
     required: false,
-    description: 'ISO timestamp. Past allowed, future rejected, must be in corridor order.',
+    description:
+      "ISO timestamp. Past allowed, future rejected, must be in corridor order.",
   })
   @IsOptional()
   @IsISO8601()
@@ -110,7 +134,8 @@ export class UpdateCheckpointDto {
 export class DispatchScheduleDto {
   @ApiProperty({
     required: false,
-    description: 'Actual departure time; defaults to now. Past allowed, future rejected.',
+    description:
+      "Actual departure time; defaults to now. Past allowed, future rejected.",
   })
   @IsOptional()
   @IsISO8601()
@@ -125,10 +150,10 @@ export class DispatchScheduleDto {
   @ApiProperty({
     required: false,
     description:
-      'Origin-yard bookings confirmed loaded; the rest are unassigned back to the pool. Omit to auto-load all.',
+      "Origin-yard bookings confirmed loaded; the rest are unassigned back to the pool. Omit to auto-load all.",
   })
   @IsOptional()
   @IsArray()
-  @IsUUID('4', { each: true })
+  @IsUUID("4", { each: true })
   loadedBookingIds?: string[];
 }

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

@@ -2991,9 +2991,27 @@ export class TrainSchedulingService {
       }
       // The train is out — every pinned wagon is ASSIGNED to this schedule and
       // stays pinned so no other schedule can pick it while it's rolling.
-      const dispatchedPhysicalIds = (schedule.trainSet?.wagons ?? [])
+      const pinnedDispatchIds = (schedule.trainSet?.wagons ?? [])
         .map((slot) => slot.physicalWagonId)
         .filter((id): id is string => Boolean(id));
+      // A built train rolls with its WHOLE consist, not just the slots that
+      // carry cargo: an empty wagon coupled to the train is physically leaving
+      // the yard too. Binding only the pinned slots left those empties behind
+      // on `current_train_schedule_id`, so the checkpoint position fix (which
+      // filters on exactly that column) never moved them and they stayed
+      // recorded at the origin yard while the train they are hooked to
+      // travelled the corridor.
+      const consistPhysicalIds = schedule.trainSet?.trainId
+        ? (
+            await manager.getRepository(Wagon).find({
+              where: { trainId: schedule.trainSet.trainId },
+              select: { id: true },
+            })
+          ).map((w) => w.id)
+        : [];
+      const dispatchedPhysicalIds = [
+        ...new Set([...pinnedDispatchIds, ...consistPhysicalIds]),
+      ];
       if (dispatchedPhysicalIds.length) {
         await manager
           .getRepository(Wagon)
@@ -3063,6 +3081,15 @@ export class TrainSchedulingService {
       // that the operator didn't load individually are auto-loaded now — the
       // train is leaving with them. Mid-corridor boarders stay PAID until the
       // operator loads them at their own yard.
+      //
+      // When the client sends the confirmed list, loading is a MANUAL decision:
+      // only the ticked bookings are stamped loaded. Anything unticked was
+      // already unassigned above, but a booking can also sit here unticked and
+      // still attached (government, or one this predicate cannot shed) — those
+      // must not be auto-loaded, or an empty wagon rides as if it carried cargo.
+      // Absent (older clients) = auto-load every origin boarder, the historic
+      // behavior.
+      const confirmedLoadedIds = dto.loadedBookingIds;
       await manager.query(
         `UPDATE freight.bookings b
             SET status = 'IN_TRANSIT',
@@ -3074,8 +3101,14 @@ export class TrainSchedulingService {
             AND b.deleted_at IS NULL
             AND b.origin_yard_id = $2
             AND b.loaded_at IS NULL
-            AND (b.status = 'PAID' OR (b.is_government = true AND b.status = 'APPROVED'))`,
-        [scheduleId, schedule.originStationId, now],
+            AND (b.status = 'PAID' OR (b.is_government = true AND b.status = 'APPROVED'))
+            AND ($4::uuid[] IS NULL OR b.id = ANY($4::uuid[]))`,
+        [
+          scheduleId,
+          schedule.originStationId,
+          now,
+          confirmedLoadedIds ? confirmedLoadedIds : null,
+        ],
       );
       // Close the booking window; any still-pending (unallocated) reservations don't ride this train.
       await manager
@@ -3173,11 +3206,19 @@ export class TrainSchedulingService {
     context: { action: string; yardLabel?: string },
   ): Promise<void> {
     if (!schedule.trainSetId) return;
-    const rows: Array<{ reference: string; loaded: string; total: string }> =
-      await this.dataSource.query(
-        `SELECT b.reference,
+    const rows: Array<{
+      bookingId: string;
+      reference: string;
+      loaded: string;
+      total: string;
+      unloadedAllocationIds: string[];
+    }> = await this.dataSource.query(
+      `SELECT b.id AS "bookingId",
+                b.reference,
                 COUNT(*) FILTER (WHERE a.status IN ('LOADED', 'DEPARTED')) AS loaded,
-                COUNT(*) AS total
+                COUNT(*) AS total,
+                ARRAY_AGG(a.id) FILTER (WHERE a.status NOT IN ('LOADED', 'DEPARTED'))
+                  AS "unloadedAllocationIds"
            FROM freight.wagon_booking_allocations a
            JOIN freight.train_set_wagons tsw ON tsw.id = a.train_set_wagon_id
            JOIN freight.bookings b ON b.id = a.booking_id
@@ -3189,18 +3230,38 @@ export class TrainSchedulingService {
           GROUP BY b.id, b.reference
          HAVING COUNT(*) FILTER (WHERE a.status IN ('LOADED', 'DEPARTED')) > 0
             AND COUNT(*) FILTER (WHERE a.status NOT IN ('LOADED', 'DEPARTED')) > 0`,
-        [schedule.trainSetId, boardingYardId],
-      );
+      [schedule.trainSetId, boardingYardId],
+    );
     if (rows.length) {
       const detail = rows
         .map((r) => `${r.reference} (${r.loaded}/${r.total} wagons loaded)`)
         .join(', ');
       const where = context.yardLabel ? ` at ${context.yardLabel}` : '';
-      throw new BadRequestException(
-        `Cannot ${context.action}: booking(s) partially loaded${where} — load every wagon ` +
+      // The message stays human-readable for logs and older clients, but the
+      // payload carries the machine-readable cut so the UI can offer the
+      // EDR-fault / customer-fault decision instead of parsing prose.
+      throw new BadRequestException({
+        statusCode: 400,
+        error: 'Bad Request',
+        code: 'PARTIALLY_LOADED_BOOKINGS',
+        message:
+          `Cannot ${context.action}: booking(s) partially loaded${where} — load every wagon ` +
           `or cancel the remainder (customer fault: cancellation fee; EDR fault: no fee, ` +
           `rebookable) first: ${detail}`,
-      );
+        partiallyLoaded: {
+          scheduleId: schedule.id,
+          boardingYardId,
+          yardLabel: context.yardLabel ?? null,
+          action: context.action,
+          bookings: rows.map((r) => ({
+            bookingId: r.bookingId,
+            reference: r.reference,
+            loadedWagons: Number(r.loaded),
+            totalWagons: Number(r.total),
+            unloadedAllocationIds: r.unloadedAllocationIds ?? [],
+          })),
+        },
+      });
     }
   }
 
@@ -3227,6 +3288,20 @@ export class TrainSchedulingService {
     }
   }
 
+  /**
+   * The log-pass twin of {@link unloadedOriginBoarderIds}: bookings that boarded
+   * at `yardId` and are still unloaded once the train has left it. Same
+   * predicate — partially-loaded bookings (loading_started_at set) are excluded
+   * because assertNoPartiallyLoadedBookings resolves those first, and government
+   * bookings can never be shed.
+   */
+  private async unloadedBoarderIdsAtYard(
+    scheduleId: string,
+    yardId: string,
+  ): Promise<string[]> {
+    return this.unloadedOriginBoarderIds(scheduleId, yardId);
+  }
+
   private async unloadedOriginBoarderIds(
     scheduleId: string,
     originYardId: string,
@@ -4702,6 +4777,24 @@ export class TrainSchedulingService {
     // skipped checkpoint log cannot smuggle an unresolved yard past the gate.
     await this.assertPassedYardsFullyLoaded(schedule, stations, dto.sequenceNo);
 
+    // Mid-corridor leave-behind. Recording THIS station means the train has
+    // left the previous one, so cargo that boarded back there has had its last
+    // chance to load: anything the operator did not tick is deallocated and
+    // returned to the pool, exactly as dispatch does for the origin yard.
+    // Origin (seq 0) is dispatch's job, so only seq >= 1 has a departed yard.
+    if (dto.loadedBookingIds && dto.sequenceNo > 0) {
+      const departedYardId = stations.find(
+        (s) => s.sequenceNo === dto.sequenceNo - 1,
+      )?.yardId;
+      if (departedYardId) {
+        const keep = new Set(dto.loadedBookingIds);
+        const candidates = await this.unloadedBoarderIdsAtYard(scheduleId, departedYardId);
+        for (const bookingId of candidates.filter((id) => !keep.has(id))) {
+          await this.unassignBooking(scheduleId, bookingId, undefined);
+        }
+      }
+    }
+
     // Upsert by (scheduleId, sequenceNo) so re-logging a station updates rather than duplicates.
     const [existing] = await this.trainCheckpointEventsRepository.findAll({
       where: { trainScheduleId: scheduleId, sequenceNo: dto.sequenceNo },
@@ -5323,6 +5416,22 @@ export class TrainSchedulingService {
           );
         }
       }
+      // Consist-only empties: coupled to the built train and bound at dispatch
+      // so the checkpoint position fix moves them, but they own no slot, so the
+      // per-slot settle above never sees them. Release them here or they stay
+      // locked to a finished schedule and no later train can pick them up.
+      // They carry no cargo, so they simply settle where the train ended up.
+      await manager
+        .getRepository(Wagon)
+        .createQueryBuilder()
+        .update(Wagon)
+        .set({
+          currentTrainScheduleId: null,
+          trainSetWagonId: null,
+          currentYardId: schedule.destinationStationId,
+        })
+        .where('current_train_schedule_id = :scheduleId', { scheduleId })
+        .execute();
       if (arrivalLogRows.length) {
         await manager.getRepository(ScheduleWagonAdjustmentLog).save(arrivalLogRows);
       }