feat(intercity): show intercity cargo across every train

Intercity bookings never get their own train — they ride whichever import/export
train passes through their corridor — so the work is scattered across other
people's schedules and there was nowhere to see it as a whole. The per-schedule
ride-along panel answers "what can THIS train carry"; this answers "what is
happening to intercity cargo".

Purely additive: the existing ride-along panel and the schedule detail page are
untouched, and loading/unloading still happens there, where the train's position
is confirmed. This is a read-only view that points back to it.

Each row carries both ends' facility status, because a booking whose origin or
destination has no equipment can never be worked there — the operator should see
that while the train is still coming, not when the load is refused. Those
bookings are counted and called out.

New GET /train-scheduling/intercity/bookings; the type is IntercityRideAlongRow,
not IntercityBookingRow, which already means the per-schedule candidate row.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/edr-freight-web/backoffice/src/services/api.ts

@@ -702,6 +702,16 @@ export const api = {
       () => TRAIN_SCHEDULING_INVALIDATIONS,
     ),
 
+    intercityBookings: endpoint<
+      void,
+      import("@/types/trainScheduling").IntercityRideAlongRow[]
+    >(
+      "train-scheduling",
+      "intercity-bookings",
+      () => trainSchedulingService.listIntercityBookings(),
+      () => ["train-scheduling", "intercity-bookings"],
+    ),
+
     intercityCandidates: endpoint<
       { scheduleId: string },
       import("@/types/trainScheduling").IntercityCandidatesResult