fix(booking-import): read the seat that KItinerary gives

KItinerary writes a flight seat as airplaneSeat and a ticket seat as
reservedTicket.ticketedSeat.seatNumber, the schema.org fields, and it
removes seat and seatNumber from a script result. segmentDetail read only
seat and seatNumber, so an imported booking lost its seat.

segmentDetail now also reads airplaneSeat, and then the ticket seat when
no other key has a value. seat and seatNumber stay first, so a booking
that already has a seat gets the same result.

server/src/nest/booking-import/kitinerary-mapper.ts

@@ -709,7 +709,12 @@ function segmentDetail(r: KiReservation): {
     }
     return undefined;
   };
-  const seat = pick('seat', 'seatNumber');
+  // KItinerary writes a flight seat as airplaneSeat and a rail seat as
+  // reservedTicket.ticketedSeat.seatNumber, and drops any other seat key.
+  const ticket = r.reservedTicket as { ticketedSeat?: { seatNumber?: unknown } } | undefined;
+  const ticketSeat = ticket?.ticketedSeat?.seatNumber;
+  const seat =
+    pick('seat', 'seatNumber', 'airplaneSeat') ?? (ticketSeat != null && ticketSeat !== '' ? ticketSeat : undefined);
   const cls = pick('class', 'bookingClass', 'fareClass', 'serviceClass', 'seatingType');
   const platform = pick('platform', 'departurePlatform');
   const price = pick('price', 'priceAmount', 'totalPrice', 'total');

server/tests/unit/nest/booking-import/kitineraryMapper.test.ts

@@ -634,3 +634,23 @@ describe('kitinerary mapper: a prompt-shaped AI lodging (#2477)', () => {
     });
   });
 });
+
+describe('kitinerary mapper: the seat as KItinerary writes it', () => {
+  it('reads a flight seat from airplaneSeat', () => {
+    const node = {
+      ...flight('CE9P8V', SFO, JFK, '2026-06-11T10:00:00', '2026-06-11T18:30:00', '450'),
+      airplaneSeat: '4D',
+    };
+    const { items } = mapReservations(legs(node), 'test.json');
+    expect(items[0].metadata).toMatchObject({ seat: '4D' });
+  });
+
+  it('reads a seat from reservedTicket.ticketedSeat.seatNumber', () => {
+    const node = {
+      ...flight('CE9P8V', SFO, JFK, '2026-06-11T10:00:00', '2026-06-11T18:30:00', '450'),
+      reservedTicket: { ticketedSeat: { seatNumber: '23A' } },
+    };
+    const { items } = mapReservations(legs(node), 'test.json');
+    expect(items[0].metadata).toMatchObject({ seat: '23A' });
+  });
+});