fix(security): 修复赠送资产薅积分三大漏洞

1. SELECT FOR UPDATE 锁定资产行，防止并发转赠竞态条件
2. 检查 RowsAffected 防止 GORM 静默失败导致空壳发货记录
3. 兑换积分时校验转赠来源，禁止转赠资产兑换积分
4. 转赠来源校验改用写库查询，避免主从延迟绕过
5. 转赠来源查询错误不再静默忽略，失败时返回错误

基于 zuncle 分支修复，额外修正了两个安全隐患：
- RedeemInventoryToPoints/RedeemInventoriesToPoints 中
  转赠记录查询从 readDB 改为 writeDB
- Count()/Find() 返回的 error 不再丢弃

internal/service/user/address_share.go

@@ -570,10 +570,11 @@ func (s *service) RedeemInventoryToPoints(ctx context.Context, userID int64, inv
 	}
 
 	// 校验转赠来源：通过转赠获得的资产不允许兑换积分（防薅积分漏洞）
-	transferCnt, _ := s.readDB.UserInventoryTransfers.WithContext(ctx).Where(
-		s.readDB.UserInventoryTransfers.InventoryID.Eq(inventoryID),
-		s.readDB.UserInventoryTransfers.ToUserID.Eq(userID),
-	).Count()
+	// 使用写库查询，避免主从延迟导致校验被绕过
+	var transferCnt int64
+	if err := s.repo.GetDbW().Raw("SELECT COUNT(*) FROM user_inventory_transfers WHERE inventory_id = ? AND to_user_id = ?", inventoryID, userID).Scan(&transferCnt).Error; err != nil {
+		return 0, err
+	}
 	if transferCnt > 0 {
 		return 0, fmt.Errorf("transfer_inventory_cannot_redeem")
 	}
@@ -659,14 +660,15 @@ func (s *service) RedeemInventoriesToPoints(ctx context.Context, userID int64, i
 	}
 
 	// 3.5 排除通过转赠获得的资产（防薅积分漏洞）
+	// 使用写库查询，避免主从延迟导致校验被绕过
 	invIDs := make([]int64, 0, len(invList))
 	for _, inv := range invList {
 		invIDs = append(invIDs, inv.ID)
 	}
-	transferredInvs, _ := s.readDB.UserInventoryTransfers.WithContext(ctx).
-		Where(s.readDB.UserInventoryTransfers.InventoryID.In(invIDs...)).
-		Where(s.readDB.UserInventoryTransfers.ToUserID.Eq(userID)).
-		Find()
+	var transferredInvs []*model.UserInventoryTransfers
+	if err := s.repo.GetDbW().Raw("SELECT * FROM user_inventory_transfers WHERE inventory_id IN ? AND to_user_id = ?", invIDs, userID).Scan(&transferredInvs).Error; err != nil {
+		return 0, err
+	}
 	transferredSet := make(map[int64]struct{}, len(transferredInvs))
 	for _, t := range transferredInvs {
 		transferredSet[t.InventoryID] = struct{}{}