add yard distances management to rule engine

- Introduced new yard distances resource with CRUD operations.
- Created migration for yard distances table with necessary constraints.
- Implemented service and repository for yard distances handling.
- Added controller for API endpoints to manage yard distances.
- Updated rule engine configuration to include yard distances.
- Enhanced rule engine resource page to support yard distance selection.
- Updated contracts and train builder pages to handle new yard distance logic.
- Added error handling utility for better error message extraction.

apps/edr-freight-web/backoffice/src/utils/errorExtractor.ts

@@ -0,0 +1,17 @@
+/**
+ * Pull the SERVER's actual error message out of a failed request.
+ *
+ * NestJS returns `{ message: string | string[] }`; a class-validator failure is
+ * the array form (joined here). Falls back to the error's own `.message` — the
+ * axios response interceptor (see `auth/http.ts`) already rewrites that to the
+ * server message, so even code paths that never see the raw response body get
+ * the real cause — then to the caller's fallback string.
+ */
+export const extractErrorMessage = (err: unknown, fallback: string): string => {
+  const msg = (err as { response?: { data?: { message?: string | string[] } } })
+    ?.response?.data?.message;
+  if (Array.isArray(msg)) return msg.filter(Boolean).join(", ");
+  if (typeof msg === "string" && msg) return msg;
+  if (err instanceof Error && err.message) return err.message;
+  return fallback;
+};