feat(bookings): add ad-hoc additional-charge module

New freight.additional_charge table, independent of BookingClearanceCharge
(unbounded per booking, free-text reason). Draft -> send issues an invoice
and notifies the customer in-app/SMS/email; settles via the standard
.invoice.paid event. Adds the Additional charges row-menu entry
next to Cancel booking, permission-gated.

Not included: the Additional Payments tab UI, add-charge modal, portal pay
flow.

apps/edr-freight-api/src/modules/billing/billing.service.ts

@@ -13,6 +13,7 @@ import { logCtx } from "@edr/api-common";
 import { DataSource, EntityManager, In, SelectQueryBuilder } from "typeorm";
 
 import { Booking } from "../bookings/entities/booking.entity";
+import { AdditionalCharge } from "../bookings/entities/additional-charge.entity";
 // Entity-only import (no module edge): portal reads resolve shipping-line
 // payers straight off the table.
 import { ShippingLineCompany } from "../shipping-lines/entities/shipping-line-company.entity";
@@ -1958,6 +1959,14 @@ export class BillingService {
         .getRepository(Booking)
         .update({ id: invoice.sourceId }, { pnrCode: billReference });
     }
+    // Same reference, for an ad-hoc additional charge — its own column, since
+    // an AdditionalCharge doesn't own a Booking-scoped `pnrCode` and a booking
+    // can carry many of these at once.
+    if (billReference && invoice.source === Freight.InvoiceSource.AdditionalCharge) {
+      await this.dataSource
+        .getRepository(AdditionalCharge)
+        .update({ id: invoice.sourceId }, { paymentReference: billReference });
+    }
 
     // Settlement is driven by the payment API (webhook/outbox → payment.succeeded);
     // billing must not simulate it. Kept for local demos only.