implement intercity booking management and booking window websocket integration

apps/edr-freight-api/src/modules/rule-engine/entities/yard.entity.ts

@@ -1,4 +1,5 @@
 import { BaseEntity } from '@edr/api-common';
+import { YardCountry } from '@edr/types';
 import { Column, Entity, Index } from 'typeorm';
 
 @Entity({ schema: 'freight', name: 'yards' })
@@ -12,8 +13,11 @@ export class Yard extends BaseEntity {
   @Column({ name: 'label', type: 'varchar', length: 100 })
   label!: string;
 
+  // Constrained to YardCountry by DTO validation + a DB CHECK constraint;
+  // route/schedule trade direction is derived from this value. Typed as the
+  // enum's literal values so plain strings from seeds/queries still fit.
   @Column({ name: 'country', type: 'varchar', length: 50 })
-  country!: string;
+  country!: `${YardCountry}`;
 
   @Column({ name: 'is_active', type: 'boolean', default: true })
   isActive!: boolean;