fix: 修复梯度佣金档位字段缺失，补全授权接口响应字段及强充有效状态

- OneTimeCommissionTierDTO 补充 operator 字段映射
- GrantCommissionTierItem 补充 dimension/stat_scope 字段（从全局配置合并）
- 系列授权列表/详情补充强充锁定状态和强充金额的有效值计算
- 同步 OpenSpec 主规范并归档变更文档

internal/model/dto/package_series_dto.go

@@ -4,6 +4,7 @@ package dto
 type OneTimeCommissionTierDTO struct {
 	Dimension string `json:"dimension" validate:"required,oneof=sales_count sales_amount" required:"true" description:"统计维度 (sales_count:销量, sales_amount:销售额)"`
 	StatScope string `json:"stat_scope" validate:"omitempty,oneof=self self_and_sub" description:"统计范围 (self:仅自己, self_and_sub:自己+下级)"`
+	Operator  string `json:"operator,omitempty" validate:"omitempty,oneof=> >= < <=" description:"阈值比较运算符（>、>=、<、<=），空值时计算引擎默认 >="`
 	Threshold int64  `json:"threshold" validate:"required,min=0" required:"true" minimum:"0" description:"达标阈值"`
 	Amount    int64  `json:"amount" validate:"required,min=0" required:"true" minimum:"0" description:"佣金金额（分）"`
 }