修复 code review 问题：DTO 内部字段、错误消息、重复代码与测试覆盖

- 删除 ExpiryBaseOverrideSet 字段的 description 标签（json:"-" 内部字段不进文档）
- ValidateExpiryBaseOverride 两处 CodeInvalidParam 补充中文错误消息
- 提取 initPackageExpiryBaseFields 消除 toResponse/toResponseWithAllocation 中的重复初始化
- 删除 order/service.go 中"行业卡永远直接激活"过时注释
- 补充 T01 系列授权 HTTP 集成测试（Create + ManagePackages 两个入口）
- 补充 T03 C 端购买和平台代购（无分配）快照集成测试
- 补充 T04 from_purchase 默认值、卡未实名仍立即激活的自动购包测试
- 新增 testutil.NewRedisClient 供激活接续测试使用

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/service/package/service.go

@@ -625,16 +625,13 @@ func (s *Service) toResponse(ctx context.Context, pkg *model.Package) *dto.Packa
 		CalendarType:            pkg.CalendarType,
 		DurationDays:            durationDays,
 		DataResetCycle:          pkg.DataResetCycle,
-		ExpiryBase:              pkg.ExpiryBase,
-		DefaultExpiryBase:       pkg.ExpiryBase,
-		DefaultExpiryBaseName:   ExpiryBaseName(pkg.ExpiryBase),
-		EffectiveExpiryBase:     pkg.ExpiryBase,
-		EffectiveExpiryBaseName: ExpiryBaseName(pkg.ExpiryBase),
-		Status:                  pkg.Status,
-		ShelfStatus:             pkg.ShelfStatus,
-		CreatedAt:               pkg.CreatedAt.Format(time.RFC3339),
-		UpdatedAt:               pkg.UpdatedAt.Format(time.RFC3339),
+		ExpiryBase:  pkg.ExpiryBase,
+		Status:      pkg.Status,
+		ShelfStatus: pkg.ShelfStatus,
+		CreatedAt:   pkg.CreatedAt.Format(time.RFC3339),
+		UpdatedAt:   pkg.UpdatedAt.Format(time.RFC3339),
 	}
+	initPackageExpiryBaseFields(resp, pkg)
 
 	userType := middleware.GetUserTypeFromContext(ctx)
 	shopID := middleware.GetShopIDFromContext(ctx)
@@ -707,16 +704,13 @@ func (s *Service) toResponseWithAllocation(_ context.Context, pkg *model.Package
 		CalendarType:            pkg.CalendarType,
 		DurationDays:            durationDays,
 		DataResetCycle:          pkg.DataResetCycle,
-		ExpiryBase:              pkg.ExpiryBase,
-		DefaultExpiryBase:       pkg.ExpiryBase,
-		DefaultExpiryBaseName:   ExpiryBaseName(pkg.ExpiryBase),
-		EffectiveExpiryBase:     pkg.ExpiryBase,
-		EffectiveExpiryBaseName: ExpiryBaseName(pkg.ExpiryBase),
-		Status:                  pkg.Status,
-		ShelfStatus:             pkg.ShelfStatus,
-		CreatedAt:               pkg.CreatedAt.Format(time.RFC3339),
-		UpdatedAt:               pkg.UpdatedAt.Format(time.RFC3339),
+		ExpiryBase:  pkg.ExpiryBase,
+		Status:      pkg.Status,
+		ShelfStatus: pkg.ShelfStatus,
+		CreatedAt:   pkg.CreatedAt.Format(time.RFC3339),
+		UpdatedAt:   pkg.UpdatedAt.Format(time.RFC3339),
 	}
+	initPackageExpiryBaseFields(resp, pkg)
 
 	if allocationMap != nil {
 		if allocation, ok := allocationMap[pkg.ID]; ok {
@@ -744,6 +738,14 @@ func (s *Service) toResponseWithAllocation(_ context.Context, pkg *model.Package
 	return resp
 }
 
+// initPackageExpiryBaseFields 初始化响应中生效条件默认字段（无分配覆盖时跟随套餐默认）。
+func initPackageExpiryBaseFields(resp *dto.PackageResponse, pkg *model.Package) {
+	resp.DefaultExpiryBase = pkg.ExpiryBase
+	resp.DefaultExpiryBaseName = ExpiryBaseName(pkg.ExpiryBase)
+	resp.EffectiveExpiryBase = pkg.ExpiryBase
+	resp.EffectiveExpiryBaseName = ExpiryBaseName(pkg.ExpiryBase)
+}
+
 func applyAllocationExpiryBase(resp *dto.PackageResponse, pkg *model.Package, allocation *model.ShopPackageAllocation) {
 	resp.ExpiryBaseOverride = allocation.ExpiryBaseOverride
 	resp.ExpiryBaseOverrideName = ExpiryBaseOverrideName(allocation.ExpiryBaseOverride)