♻️ refactor(routes): 优化车型字段类型定义

- 将vehicleType字段从string类型改为VehicleType枚举类型
- 使用typeorm的enum类型映射数据库字段，增强类型安全性

src/server/modules/routes/route.entity.ts

@@ -1,6 +1,7 @@
 import { Entity, PrimaryGeneratedColumn, Column, ManyToOne, JoinColumn, CreateDateColumn, UpdateDateColumn } from 'typeorm';
 import { ActivityEntity } from '@/server/modules/activities/activity.entity';
 import { DeleteStatus, DisabledStatus } from '@/share/types';
+import { VehicleType } from './route.schema';
 
 @Entity({ name: 'routes' })
 export class RouteEntity {
@@ -28,8 +29,8 @@ export class RouteEntity {
   @Column({ name: 'departure_time', type: 'timestamp', comment: '出发时间' })
   departureTime!: Date;
 
-  @Column({ name: 'vehicle_type', type: 'varchar', length: 50, comment: '车型' })
-  vehicleType!: string;
+  @Column({ name: 'vehicle_type', type: 'enum', enum: VehicleType, comment: '车型' })
+  vehicleType!: VehicleType;
 
   @Column({ name: 'price', type: 'decimal', precision: 10, scale: 2, comment: '价格' })
   price!: number;