♻️ refactor(redemption-codes): update batch association in RedemptionCode entity

- replace Batch entity reference with WechatCouponStock entity
- modify ManyToOne relationship to use WechatCouponStock
- add explicit referencedColumnName for batch_id join column
- change batch property from optional to required

src/server/modules/redemption-codes/redemption-code.entity.ts

@@ -1,5 +1,5 @@
 import { Entity, PrimaryGeneratedColumn, Column, CreateDateColumn, UpdateDateColumn, ManyToOne, JoinColumn } from 'typeorm';
-import { Batch } from '../batches/batch.entity';
+import { WechatCouponStock } from '@/server/modules/wechat-pay/wechat-coupon-stock.entity';
 
 export enum RedemptionStatus {
   UNUSED = 0,
@@ -44,7 +44,7 @@ export class RedemptionCode {
   updatedAt!: Date;
 
   // 关联批次
-  @ManyToOne(() => Batch)
-  @JoinColumn({ name: 'batch_id' })
-  batch?: Batch;
+  @ManyToOne(() => WechatCouponStock)
+  @JoinColumn({ name: 'batch_id', referencedColumnName: 'id' })
+  batch!: WechatCouponStock;
 }