feat(train): enhance train history and scheduling features

- Added a reason field to train history entries for detach/maintenance actions.
- Updated TrainHistoryPanel to display the reason for wagon detachments.
- Introduced per-wagon load/unload functionality in ScheduleWorkspacePanel with a modal for managing individual wagons.
- Implemented API endpoints for loading and unloading specific wagons, including the ability to cancel remaining wagons with a reason.
- Refactored detach request handling in TrainBuilderDetailPage to streamline the process and remove the approval flow, requiring a reason for detachments.
- Updated types and services to support new wagon loading/unloading features and booking wagon retrieval.

apps/edr-freight-web/backoffice/src/services/trainBuilder.service.ts

@@ -311,6 +311,11 @@ export interface TrainHistoryEntry {
   actor: string | null;
   /** Set when the change came from a trip (schedule); null = train-builder edit. */
   scheduleReference: string | null;
+  /**
+   * Why the wagon left the consist — required for a detach / maintenance move
+   * on a SCHEDULED run. Null for trip events and unscheduled builder edits.
+   */
+  reason: string | null;
   occurredAt: string;
 }
 
@@ -436,37 +441,20 @@ export const trainBuilderService = {
     }),
   assignWagons: (id: string, wagonIds: string[]) =>
     apiClient.post<TrainComposition>(`${BASE}/${id}/wagons`, { wagonIds }),
-  removeWagon: (id: string, wagonId: string) =>
-    apiClient.delete<TrainComposition>(`${BASE}/${id}/wagons/${wagonId}`),
+  /** `reason` is required by the API while the train is on a SCHEDULED run. */
+  removeWagon: (id: string, wagonId: string, reason?: string) =>
+    apiClient.delete<TrainComposition>(`${BASE}/${id}/wagons/${wagonId}`, {
+      data: reason ? { reason } : undefined,
+    }),
   /** Detach a wagon and move it to MAINTENANCE status. */
   /** `note` is the maintenance reason — recorded with the train it came off. */
   sendWagonToMaintenance: (id: string, wagonId: string, note?: string) =>
     apiClient.post<TrainComposition>(`${BASE}/${id}/wagons/${wagonId}/maintenance`, {
       note,
     }),
-  /** Requests to detach a wagon from a SCHEDULED train, newest first. */
+  /** Detach/maintenance audit rows of a SCHEDULED-run train, newest first. */
   detachRequests: (id: string) =>
     apiClient.get<WagonDetachRequestRow[]>(`${BASE}/${id}/detach-requests`),
-  /** File a detach/maintenance approval request (reason required). */
-  createDetachRequest: (
-    id: string,
-    wagonId: string,
-    payload: { action: "DETACH" | "MAINTENANCE"; reason: string },
-  ) =>
-    apiClient.post<WagonDetachRequestRow>(
-      `${BASE}/${id}/wagons/${wagonId}/detach-requests`,
-      payload,
-    ),
-  /** Approve a pending request — executes the detach immediately. */
-  approveDetachRequest: (id: string, requestId: string, note?: string) =>
-    apiClient.post<TrainComposition>(`${BASE}/${id}/detach-requests/${requestId}/approve`, {
-      note,
-    }),
-  /** Reject a pending request — a note explaining why is required. */
-  rejectDetachRequest: (id: string, requestId: string, note: string) =>
-    apiClient.post<TrainComposition>(`${BASE}/${id}/detach-requests/${requestId}/reject`, {
-      note,
-    }),
   reorderWagons: (id: string, wagonIds: string[]) =>
     apiClient.post<TrainComposition>(`${BASE}/${id}/reorder-wagons`, { wagonIds }),
   /** Park the train indefinitely — only allowed with no active schedule. */