feat: add contract extension request functionality

- Implemented  method in  to allow customers to request an extension for expired contracts.
- Added  component in  for users to initiate extension requests.
- Updated  to include logic for handling extension requests for expired contracts.
- Enhanced  to display extension request options and status.
- Created migration to add  and  columns to the contracts table.
- Added unit tests for contract extension request and handling in .
- Defined DTOs for request and extension in .
- Updated types in  to include new fields related to contract extensions.

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

@@ -171,7 +171,7 @@ describe('wagon-plan.util', () => {
     expect(validateContainerPlacements([booking], plan, placements)).toEqual([]);
   });
 
-  it('rejects 20ft container over max individual weight', () => {
+  it('rejects a container over its line weight-limit-rule capacity', () => {
     const booking = makeContainerBooking('c20', [{ quantity: 2, wagonsRequired: 1, vgmPerUnitTons: 35 }]);
     const units = expandBookingContainerUnits([booking]);
     const placements = units.map((unit, index) => ({
@@ -182,11 +182,29 @@ describe('wagon-plan.util', () => {
     }));
 
     const violations = validate20ftContainerRules(units, placements, {
-      max20ftContainerWeightTons: 30,
+      maxContainerWeightTonsByLineId: { [units[0]!.bookingContainerId]: 30 },
       max20ftPairWeightDiffTons: 10,
     });
 
-    expect(violations.some((v) => v.includes('exceeds max 30T'))).toBe(true);
+    expect(violations.filter((v) => v.includes('weight limit rule capacity of 30T'))).toHaveLength(2);
+  });
+
+  it('applies no per-box ceiling to a line without a weight-limit-rule capacity', () => {
+    const booking = makeContainerBooking('c20b', [{ quantity: 2, wagonsRequired: 1, vgmPerUnitTons: 35 }]);
+    const units = expandBookingContainerUnits([booking]);
+    const placements = units.map((unit, index) => ({
+      bookingContainerId: unit.bookingContainerId,
+      unitIndex: unit.unitIndex,
+      sequenceNo: 1,
+      containerNumber: `CNTR-${index + 1}`,
+    }));
+
+    const violations = validate20ftContainerRules(units, placements, {
+      maxContainerWeightTonsByLineId: {},
+      max20ftPairWeightDiffTons: 10,
+    });
+
+    expect(violations).toEqual([]);
   });
 
   it('rejects 20ft pair when weight difference exceeds limit', () => {
@@ -204,7 +222,6 @@ describe('wagon-plan.util', () => {
     }));
 
     const violations = validate20ftContainerRules(units, placements, {
-      max20ftContainerWeightTons: 30,
       max20ftPairWeightDiffTons: 10,
     });