enhance shipment form and booking process

apps/edr-freight-api/src/modules/train-scheduling/train-capacity.util.spec.ts

@@ -7,6 +7,7 @@ import {
   grossWagonWeightTons,
   minLocomotiveLimits,
   sizePartialOfferWagons,
+  trainSetLocomotiveLimits,
 } from './train-capacity.util';
 
 describe('train-capacity.util', () => {
@@ -205,6 +206,37 @@ describe('train-capacity.util', () => {
     expect(limits?.overageToleranceTons).toBe(20);
   });
 
+  it('ignores unconfigured (null) tolerances instead of zeroing the set (S-2026-00024)', () => {
+    // LOCO-019 had 90T tolerance, LOCO-020 had none configured: the set must
+    // keep the 90, not collapse to 0 and reject 3547.6T on a 3500T train.
+    const limits = minLocomotiveLimits([
+      { maxPullWeightTons: 3500, maxTrainLengthMeters: 760, overageToleranceTons: 90 },
+      { maxPullWeightTons: 3500, maxTrainLengthMeters: 760, overageToleranceTons: null },
+    ]);
+    expect(limits?.overageToleranceTons).toBe(90);
+    // All unconfigured → no tolerance.
+    const none = minLocomotiveLimits([
+      { maxPullWeightTons: 3500, maxTrainLengthMeters: 760 },
+    ]);
+    expect(none?.overageToleranceTons).toBe(0);
+  });
+
+  it('trainSetLocomotiveLimits prefers link rows and falls back to the legacy single loco', () => {
+    const l1 = { maxPullWeightTons: 3500, maxTrainLengthMeters: 760, overageToleranceTons: 90 };
+    const l2 = { maxPullWeightTons: 3600, maxTrainLengthMeters: 700, overageToleranceTons: null };
+    expect(
+      trainSetLocomotiveLimits({ locomotive: null, locomotives: [{ locomotive: l1 }, { locomotive: l2 }] }),
+    ).toEqual({
+      maxPullWeightTons: 3500,
+      maxTrainLengthMeters: 700,
+      overageToleranceTons: 90,
+      overageToleranceMeters: 0,
+    });
+    expect(trainSetLocomotiveLimits({ locomotive: l1 })?.maxPullWeightTons).toBe(3500);
+    expect(trainSetLocomotiveLimits(null)).toBeNull();
+    expect(trainSetLocomotiveLimits({ locomotive: null, locomotives: [] })).toBeNull();
+  });
+
   describe('sizePartialOfferWagons', () => {
     it('sizes a bulk split by the WEIGHT axis when the pull limit binds, not wagon slots', () => {
       // The 3500T-train scenario: two 1000T bookings boarded gross (each 15 PW2