feat: 付费体系重构 P0 - 配额独立化/简历付费下载/PDF生成

backend/src/modules/payment/payment-order.schema.ts

@@ -27,12 +27,18 @@ export class PaymentOrder {
   @Prop({ default: 'pending' })
   status: string
 
+  @Prop({ default: 'membership' })
+  type: string            // membership | interview | optimize | download
+
   @Prop({ default: 'growth' })
   plan: string            // growth | sprint
 
   @Prop({ default: 'native' })
   channel: string         // native | jsapi
 
+  @Prop({ type: Object })
+  metadata?: Record<string, any>
+
   @Prop()
   paidAt?: Date