修复: GET /v1/admin/promo/price/list 字段不匹配导致 400

前端发 rule_id/subscribe_id (均可选), 后端 API 定义为 promo_rule_id
(required), 直接返回 "PromoRuleId is a required field"。

对齐前端约定 (与 usage/list 命名一致):
- API: promo_rule_id(required) → rule_id + subscribe_id, 均可选
- model.QueryPriceList: 改为接 PriceFilter, 按条件过滤
- 同步 fake mock 与校验测试签名

internal/model/promo/model.go

@@ -24,7 +24,7 @@ type Model interface {
 	UpsertPrices(ctx context.Context, ruleId int64, items []*SubscribePromo) error
 	FindPrice(ctx context.Context, id int64) (*SubscribePromo, error)
 	DeletePrice(ctx context.Context, id int64) error
-	QueryPriceList(ctx context.Context, ruleId int64, page, size int) (int64, []*SubscribePromo, error)
+	QueryPriceList(ctx context.Context, params PriceFilter) (int64, []*SubscribePromo, error)
 	QueryUsageList(ctx context.Context, params UsageFilter) (int64, []*Usage, error)
 	Transaction(ctx context.Context, fn func(db *gorm.DB) error) error
 }
@@ -38,6 +38,13 @@ type UsageFilter struct {
 	OrderNo     string
 }
 
+type PriceFilter struct {
+	Page        int
+	Size        int
+	RuleId      int64
+	SubscribeId int64
+}
+
 type defaultPromoModel struct {
 	db *gorm.DB
 }
@@ -164,20 +171,26 @@ func (m *defaultPromoModel) DeletePrice(ctx context.Context, id int64) error {
 	return m.db.WithContext(ctx).Delete(&SubscribePromo{}, id).Error
 }
 
-func (m *defaultPromoModel) QueryPriceList(ctx context.Context, ruleId int64, page, size int) (int64, []*SubscribePromo, error) {
-	if page <= 0 {
-		page = 1
+func (m *defaultPromoModel) QueryPriceList(ctx context.Context, params PriceFilter) (int64, []*SubscribePromo, error) {
+	if params.Page <= 0 {
+		params.Page = 1
 	}
-	if size <= 0 {
-		size = 10
+	if params.Size <= 0 {
+		params.Size = 10
 	}
 	var total int64
 	var list []*SubscribePromo
-	db := m.db.WithContext(ctx).Model(&SubscribePromo{}).Where("promo_rule_id = ?", ruleId)
+	db := m.db.WithContext(ctx).Model(&SubscribePromo{})
+	if params.RuleId > 0 {
+		db = db.Where("promo_rule_id = ?", params.RuleId)
+	}
+	if params.SubscribeId > 0 {
+		db = db.Where("subscribe_id = ?", params.SubscribeId)
+	}
 	if err := db.Count(&total).Error; err != nil {
 		return 0, nil, err
 	}
-	err := db.Order("id DESC").Limit(size).Offset((page - 1) * size).Find(&list).Error
+	err := db.Order("id DESC").Limit(params.Size).Offset((params.Page - 1) * params.Size).Find(&list).Error
 	return total, list, err
 }