feat: implement staff price adjustment feature for bookings

packages/types/src/freight/index.ts

@@ -360,6 +360,11 @@ export interface IBooking extends BaseEntity {
   /** Null for general contracts at creation — the date is chosen per order. */
   scheduledDate: string;
   totalAmount: number;
+  /** Staff-adjusted total that overrides totalAmount for the customer, if set. */
+  adjustedTotalAmount?: number | null;
+  adjustedByStaffId?: string | null;
+  adjustedAt?: string | null;
+  adjustmentReason?: string | null;
   paymentStatus: PaymentStatus;
 
   shippingLineId?: string | null;