feat: Refactor order snapshot handling and introduce structured snapshot types

- Added new structured snapshot types for orders and order items to improve data integrity and clarity. - Updated the Order and OrderItem models to use the new JSONType for snapshots. - Refactored tests to accommodate the new snapshot structure, ensuring compatibility with legacy data. - Enhanced the OrdersSnapshot struct to support multiple snapshot types and maintain backward compatibility. - Introduced new fields for order items and orders to capture detailed snapshot information for auditing and historical display.
update llm.txt
2025-12-22 21:11:33 +08:00 · 2025-12-22 21:11:13 +08:00 · 2025-12-22 20:59:24 +08:00 · 2025-12-22 19:27:31 +08:00 · 2025-12-22 18:56:44 +08:00
22 changed files with 735 additions and 342 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ build/*
 .vscode
 .idea
 tmp/
+.cache/
 .gocache/
 .gotmp/
 docker-compose.yml
--- a/backend/app/http/tenant/dto/media_asset_admin.go
+++ b/backend/app/http/tenant/dto/media_asset_admin.go
@@ -1,6 +1,10 @@
 package dto

-import "time"
+import (
+	"time"
+
+	"quyun/v2/pkg/consts"
+)

 // AdminMediaAssetUploadInitForm defines payload for tenant-admin to initialize a media asset upload.
 type AdminMediaAssetUploadInitForm struct {
@@ -10,7 +14,7 @@ type AdminMediaAssetUploadInitForm struct {

 	// Variant indicates whether this asset is a main or preview product.
 	// Allowed: main/preview; default is main.
-	Variant string `json:"variant,omitempty"`
+	Variant *consts.MediaAssetVariant `json:"variant,omitempty"`

 	// SourceAssetID links a preview product to its main asset; only meaningful when variant=preview.
 	SourceAssetID *int64 `json:"source_asset_id,omitempty"`
--- a/backend/app/services/content.go
+++ b/backend/app/services/content.go
@@ -34,13 +34,13 @@ type ContentDetailResult struct {
 	HasAccess bool
 }

-func requiredMediaAssetVariantForRole(role consts.ContentAssetRole) string {
+func requiredMediaAssetVariantForRole(role consts.ContentAssetRole) consts.MediaAssetVariant {
 	switch role {
 	case consts.ContentAssetRolePreview:
-		return mediaAssetVariantPreview
+		return consts.MediaAssetVariantPreview
 	default:
 		// main/cover 一律要求 main 产物，避免误把 preview 绑定成正片/封面。
-		return mediaAssetVariantMain
+		return consts.MediaAssetVariantMain
 	}
 }

@@ -226,23 +226,9 @@ func (s *content) AttachAsset(ctx context.Context, tenantID, userID, contentID,
 	}

 	// C2 规则：preview 必须绑定独立产物（media_assets.variant=preview），main/cover 必须为 main。
-	var assetRow struct {
-		Variant       string `gorm:"column:variant"`
-		SourceAssetID *int64 `gorm:"column:source_asset_id"`
-	}
-	if err := _db.WithContext(ctx).
-		Table(models.TableNameMediaAsset).
-		Select("variant, source_asset_id").
-		Where("tenant_id = ? AND id = ? AND deleted_at IS NULL", tenantID, assetID).
-		Take(&assetRow).Error; err != nil {
-		if errors.Is(err, gorm.ErrRecordNotFound) {
-			return nil, errorx.ErrRecordNotFound.WithMsg("media asset not found")
-		}
-		return nil, err
-	}
-	variant := assetRow.Variant
+	variant := asset.Variant
 	if variant == "" {
-		variant = mediaAssetVariantMain
+		variant = consts.MediaAssetVariantMain
 	}
 	requiredVariant := requiredMediaAssetVariantForRole(role)
 	if variant != requiredVariant {
@@ -250,31 +236,29 @@ func (s *content) AttachAsset(ctx context.Context, tenantID, userID, contentID,
 	}
 	// 关联规则：preview 产物必须声明来源 main；main/cover 不允许带来源。
 	if role == consts.ContentAssetRolePreview {
-		if assetRow.SourceAssetID == nil || *assetRow.SourceAssetID <= 0 {
+		if asset.SourceAssetID <= 0 {
 			return nil, errorx.ErrPreconditionFailed.WithMsg("preview asset must have source_asset_id")
 		}
-		var srcRow struct {
-			Variant string `gorm:"column:variant"`
-		}
-		if err := _db.WithContext(ctx).
-			Table(models.TableNameMediaAsset).
-			Select("variant").
-			Where("tenant_id = ? AND id = ? AND deleted_at IS NULL", tenantID, *assetRow.SourceAssetID).
-			Take(&srcRow).Error; err != nil {
+		src, err := queryAsset.Where(
+			tblAsset.TenantID.Eq(tenantID),
+			tblAsset.ID.Eq(asset.SourceAssetID),
+			tblAsset.DeletedAt.IsNull(),
+		).First()
+		if err != nil {
 			if errors.Is(err, gorm.ErrRecordNotFound) {
 				return nil, errorx.ErrRecordNotFound.WithMsg("preview source asset not found")
 			}
 			return nil, err
 		}
-		srcVariant := srcRow.Variant
+		srcVariant := src.Variant
 		if srcVariant == "" {
-			srcVariant = mediaAssetVariantMain
+			srcVariant = consts.MediaAssetVariantMain
 		}
-		if srcVariant != mediaAssetVariantMain {
+		if srcVariant != consts.MediaAssetVariantMain {
 			return nil, errorx.ErrPreconditionFailed.WithMsg("preview source asset must be main variant")
 		}
 	} else {
-		if assetRow.SourceAssetID != nil && *assetRow.SourceAssetID > 0 {
+		if asset.SourceAssetID > 0 {
 			return nil, errorx.ErrPreconditionFailed.WithMsg("main/cover asset must not have source_asset_id")
 		}
 	}
--- a/backend/app/services/media_asset.go
+++ b/backend/app/services/media_asset.go
@@ -31,11 +31,6 @@ import (
 //	@provider
 type mediaAsset struct{}

-const (
-	mediaAssetVariantMain    = "main"
-	mediaAssetVariantPreview = "preview"
-)
-
 func mediaAssetTransitionAllowed(from, to consts.MediaAssetStatus) bool {
 	switch from {
 	case consts.MediaAssetStatusUploaded:
@@ -82,11 +77,11 @@ func (s *mediaAsset) AdminUploadInit(ctx context.Context, tenantID, operatorUser
 		return nil, errorx.ErrInvalidParameter.WithMsg("invalid type")
 	}

-	variant := strings.TrimSpace(strings.ToLower(form.Variant))
-	if variant == "" {
-		variant = mediaAssetVariantMain
+	variant := consts.MediaAssetVariantMain
+	if form.Variant != nil {
+		variant = *form.Variant
 	}
-	if variant != mediaAssetVariantMain && variant != mediaAssetVariantPreview {
+	if variant == "" || !variant.IsValid() {
 		return nil, errorx.ErrInvalidParameter.WithMsg("invalid variant")
 	}

@@ -94,7 +89,7 @@ func (s *mediaAsset) AdminUploadInit(ctx context.Context, tenantID, operatorUser
 	if form.SourceAssetID != nil {
 		sourceAssetID = *form.SourceAssetID
 	}
-	if variant == mediaAssetVariantMain {
+	if variant == consts.MediaAssetVariantMain {
 		if sourceAssetID != 0 {
 			return nil, errorx.ErrInvalidParameter.WithMsg("source_asset_id is only allowed for preview variant")
 		}
@@ -104,24 +99,23 @@ func (s *mediaAsset) AdminUploadInit(ctx context.Context, tenantID, operatorUser
 			return nil, errorx.ErrInvalidParameter.WithMsg("source_asset_id is required for preview variant")
 		}
 		// 校验来源资源存在、同租户、未删除、且为 main 产物。
-		var srcRow struct {
-			Variant string `gorm:"column:variant"`
-		}
-		if err := _db.WithContext(ctx).
-			Table(models.TableNameMediaAsset).
-			Select("variant").
-			Where("tenant_id = ? AND id = ? AND deleted_at IS NULL", tenantID, sourceAssetID).
-			Take(&srcRow).Error; err != nil {
+		tbl, query := models.MediaAssetQuery.QueryContext(ctx)
+		src, err := query.Where(
+			tbl.TenantID.Eq(tenantID),
+			tbl.ID.Eq(sourceAssetID),
+			tbl.DeletedAt.IsNull(),
+		).First()
+		if err != nil {
 			if errors.Is(err, gorm.ErrRecordNotFound) {
 				return nil, errorx.ErrRecordNotFound.WithMsg("source media asset not found")
 			}
 			return nil, err
 		}
-		srcVariant := srcRow.Variant
+		srcVariant := src.Variant
 		if srcVariant == "" {
-			srcVariant = mediaAssetVariantMain
+			srcVariant = consts.MediaAssetVariantMain
 		}
-		if srcVariant != mediaAssetVariantMain {
+		if srcVariant != consts.MediaAssetVariantMain {
 			return nil, errorx.ErrPreconditionFailed.WithMsg("source asset must be main variant")
 		}
 	}
@@ -163,16 +157,18 @@ func (s *mediaAsset) AdminUploadInit(ctx context.Context, tenantID, operatorUser
 	}

 	// variant/source_asset_id 目前为 DB 新增字段；由于 models 为 gen 产物，这里用 SQL 更新列值。
-	updates := map[string]any{
-		"variant": variant,
+	tbl, query := models.MediaAssetQuery.QueryContext(ctx)
+	// variant/source_asset_id 已生成模型字段，使用 UpdateSimple 保持类型安全。
+	assigns := []field.AssignExpr{
+		tbl.Variant.Value(variant),
 	}
 	if sourceAssetID > 0 {
-		updates["source_asset_id"] = sourceAssetID
+		assigns = append(assigns, tbl.SourceAssetID.Value(sourceAssetID))
 	}
-	if err := _db.WithContext(ctx).
-		Model(&models.MediaAsset{}).
-		Where("id = ? AND tenant_id = ?", m.ID, tenantID).
-		Updates(updates).Error; err != nil {
+	if _, err := query.Where(
+		tbl.ID.Eq(m.ID),
+		tbl.TenantID.Eq(tenantID),
+	).UpdateSimple(assigns...); err != nil {
 		return nil, pkgerrors.Wrap(err, "update media asset variant/source_asset_id failed")
 	}

@@ -224,12 +220,16 @@ func (s *mediaAsset) AdminUploadComplete(

 	var out models.MediaAsset

-	err := _db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-		var m models.MediaAsset
-		if err := tx.
+	err := models.Q.Transaction(func(tx *models.Query) error {
+		tbl, query := tx.MediaAsset.QueryContext(ctx)
+		m, err := query.
 			Clauses(clause.Locking{Strength: "UPDATE"}).
-			Where("tenant_id = ? AND id = ?", tenantID, assetID).
-			First(&m).Error; err != nil {
+			Where(
+				tbl.TenantID.Eq(tenantID),
+				tbl.ID.Eq(assetID),
+			).
+			First()
+		if err != nil {
 			if errors.Is(err, gorm.ErrRecordNotFound) {
 				return errorx.ErrRecordNotFound.WithMsg("media asset not found")
 			}
@@ -244,7 +244,7 @@ func (s *mediaAsset) AdminUploadComplete(
 		// 幂等：重复 upload_complete 时返回现态。
 		switch m.Status {
 		case consts.MediaAssetStatusProcessing, consts.MediaAssetStatusReady, consts.MediaAssetStatusFailed:
-			out = m
+			out = *m
 			return nil
 		case consts.MediaAssetStatusUploaded:
 			// allowed
@@ -281,20 +281,18 @@ func (s *mediaAsset) AdminUploadComplete(
 		if !mediaAssetTransitionAllowed(m.Status, consts.MediaAssetStatusProcessing) {
 			return errorx.ErrStatusConflict.WithMsg("invalid media asset status transition")
 		}
-		if err := tx.Model(&models.MediaAsset{}).
-			Where("id = ?", m.ID).
-			Updates(map[string]any{
-				"status":     consts.MediaAssetStatusProcessing,
-				"meta":       types.JSON(metaBytes),
-				"updated_at": now,
-			}).Error; err != nil {
+		if _, err := query.Where(tbl.ID.Eq(m.ID)).Updates(map[string]any{
+			"status":     consts.MediaAssetStatusProcessing,
+			"meta":       types.JSON(metaBytes),
+			"updated_at": now,
+		}); err != nil {
 			return err
 		}

 		m.Status = consts.MediaAssetStatusProcessing
 		m.Meta = types.JSON(metaBytes)
 		m.UpdatedAt = now
-		out = m
+		out = *m

 		// 触发异步处理（当前为 stub）：后续接入队列/任务系统时在此处落任务并保持幂等。
 		logrus.WithFields(logrus.Fields{
@@ -328,12 +326,16 @@ func (s *mediaAsset) ProcessSuccess(
 	}

 	var out models.MediaAsset
-	err := _db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-		var m models.MediaAsset
-		if err := tx.
+	err := models.Q.Transaction(func(tx *models.Query) error {
+		tbl, query := tx.MediaAsset.QueryContext(ctx)
+		m, err := query.
 			Clauses(clause.Locking{Strength: "UPDATE"}).
-			Where("tenant_id = ? AND id = ?", tenantID, assetID).
-			First(&m).Error; err != nil {
+			Where(
+				tbl.TenantID.Eq(tenantID),
+				tbl.ID.Eq(assetID),
+			).
+			First()
+		if err != nil {
 			if errors.Is(err, gorm.ErrRecordNotFound) {
 				return errorx.ErrRecordNotFound.WithMsg("media asset not found")
 			}
@@ -343,7 +345,7 @@ func (s *mediaAsset) ProcessSuccess(
 			return errorx.ErrPreconditionFailed.WithMsg("media asset deleted")
 		}
 		if m.Status == consts.MediaAssetStatusReady {
-			out = m
+			out = *m
 			return nil
 		}
 		if !mediaAssetTransitionAllowed(m.Status, consts.MediaAssetStatusReady) {
@@ -366,19 +368,17 @@ func (s *mediaAsset) ProcessSuccess(
 			metaBytes = []byte("{}")
 		}

-		if err := tx.Model(&models.MediaAsset{}).
-			Where("id = ?", m.ID).
-			Updates(map[string]any{
-				"status":     consts.MediaAssetStatusReady,
-				"meta":       types.JSON(metaBytes),
-				"updated_at": now,
-			}).Error; err != nil {
+		if _, err := query.Where(tbl.ID.Eq(m.ID)).Updates(map[string]any{
+			"status":     consts.MediaAssetStatusReady,
+			"meta":       types.JSON(metaBytes),
+			"updated_at": now,
+		}); err != nil {
 			return err
 		}
 		m.Status = consts.MediaAssetStatusReady
 		m.Meta = types.JSON(metaBytes)
 		m.UpdatedAt = now
-		out = m
+		out = *m
 		return nil
 	})
 	if err != nil {
@@ -403,12 +403,16 @@ func (s *mediaAsset) ProcessFailed(
 	}

 	var out models.MediaAsset
-	err := _db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-		var m models.MediaAsset
-		if err := tx.
+	err := models.Q.Transaction(func(tx *models.Query) error {
+		tbl, query := tx.MediaAsset.QueryContext(ctx)
+		m, err := query.
 			Clauses(clause.Locking{Strength: "UPDATE"}).
-			Where("tenant_id = ? AND id = ?", tenantID, assetID).
-			First(&m).Error; err != nil {
+			Where(
+				tbl.TenantID.Eq(tenantID),
+				tbl.ID.Eq(assetID),
+			).
+			First()
+		if err != nil {
 			if errors.Is(err, gorm.ErrRecordNotFound) {
 				return errorx.ErrRecordNotFound.WithMsg("media asset not found")
 			}
@@ -418,7 +422,7 @@ func (s *mediaAsset) ProcessFailed(
 			return errorx.ErrPreconditionFailed.WithMsg("media asset deleted")
 		}
 		if m.Status == consts.MediaAssetStatusFailed {
-			out = m
+			out = *m
 			return nil
 		}
 		if !mediaAssetTransitionAllowed(m.Status, consts.MediaAssetStatusFailed) {
@@ -438,19 +442,17 @@ func (s *mediaAsset) ProcessFailed(
 			metaBytes = []byte("{}")
 		}

-		if err := tx.Model(&models.MediaAsset{}).
-			Where("id = ?", m.ID).
-			Updates(map[string]any{
-				"status":     consts.MediaAssetStatusFailed,
-				"meta":       types.JSON(metaBytes),
-				"updated_at": now,
-			}).Error; err != nil {
+		if _, err := query.Where(tbl.ID.Eq(m.ID)).Updates(map[string]any{
+			"status":     consts.MediaAssetStatusFailed,
+			"meta":       types.JSON(metaBytes),
+			"updated_at": now,
+		}); err != nil {
 			return err
 		}
 		m.Status = consts.MediaAssetStatusFailed
 		m.Meta = types.JSON(metaBytes)
 		m.UpdatedAt = now
-		out = m
+		out = *m
 		return nil
 	})
 	if err != nil {
@@ -475,12 +477,16 @@ func (s *mediaAsset) AdminDelete(ctx context.Context, tenantID, operatorUserID,
 	}).Info("services.media_asset.admin.delete")

 	var out models.MediaAsset
-	err := _db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-		var m models.MediaAsset
-		if err := tx.
+	err := models.Q.Transaction(func(tx *models.Query) error {
+		tbl, query := tx.MediaAsset.QueryContext(ctx)
+		m, err := query.
 			Clauses(clause.Locking{Strength: "UPDATE"}).
-			Where("tenant_id = ? AND id = ?", tenantID, assetID).
-			First(&m).Error; err != nil {
+			Where(
+				tbl.TenantID.Eq(tenantID),
+				tbl.ID.Eq(assetID),
+			).
+			First()
+		if err != nil {
 			if errors.Is(err, gorm.ErrRecordNotFound) {
 				return errorx.ErrRecordNotFound.WithMsg("media asset not found")
 			}
@@ -489,7 +495,7 @@ func (s *mediaAsset) AdminDelete(ctx context.Context, tenantID, operatorUserID,

 		// 幂等：已删除直接返回。
 		if m.DeletedAt.Valid || m.Status == consts.MediaAssetStatusDeleted {
-			out = m
+			out = *m
 			return nil
 		}

@@ -497,22 +503,20 @@ func (s *mediaAsset) AdminDelete(ctx context.Context, tenantID, operatorUserID,
 			return errorx.ErrStatusConflict.WithMsg("invalid media asset status transition")
 		}

-		if err := tx.Model(&models.MediaAsset{}).
-			Where("id = ?", m.ID).
-			Updates(map[string]any{
-				"status":     consts.MediaAssetStatusDeleted,
-				"updated_at": now,
-			}).Error; err != nil {
+		if _, err := query.Where(tbl.ID.Eq(m.ID)).Updates(map[string]any{
+			"status":     consts.MediaAssetStatusDeleted,
+			"updated_at": now,
+		}); err != nil {
 			return err
 		}

-		if err := tx.Delete(&m).Error; err != nil {
+		if _, err := query.Where(tbl.ID.Eq(m.ID)).Delete(); err != nil {
 			return err
 		}

 		m.Status = consts.MediaAssetStatusDeleted
 		m.UpdatedAt = now
-		out = m
+		out = *m
 		return nil
 	})
 	if err != nil {
--- a/backend/app/services/media_asset_test.go
+++ b/backend/app/services/media_asset_test.go
@@ -53,9 +53,10 @@ func (s *MediaAssetTestSuite) Test_AdminUploadInit_VariantAndSource() {

 		Convey("main variant 不允许 source_asset_id", func() {
 			src := int64(123)
+			v := consts.MediaAssetVariantMain
 			_, err := MediaAsset.AdminUploadInit(ctx, tenantID, userID, &tenant_dto.AdminMediaAssetUploadInitForm{
 				Type:          "video",
-				Variant:       "main",
+				Variant:       &v,
 				SourceAssetID: &src,
 			}, now)
 			So(err, ShouldNotBeNil)
@@ -65,9 +66,10 @@ func (s *MediaAssetTestSuite) Test_AdminUploadInit_VariantAndSource() {
 		})

 		Convey("preview variant 必须带 source_asset_id", func() {
+			v := consts.MediaAssetVariantPreview
 			_, err := MediaAsset.AdminUploadInit(ctx, tenantID, userID, &tenant_dto.AdminMediaAssetUploadInitForm{
 				Type:    "video",
-				Variant: "preview",
+				Variant: &v,
 			}, now)
 			So(err, ShouldNotBeNil)
 			var appErr *errorx.AppError
@@ -94,9 +96,10 @@ func (s *MediaAssetTestSuite) Test_AdminUploadInit_VariantAndSource() {
 			_, err := s.DB.ExecContext(ctx, "UPDATE media_assets SET variant = 'preview' WHERE tenant_id = $1 AND id = $2", tenantID, src.ID)
 			So(err, ShouldBeNil)

+			v := consts.MediaAssetVariantPreview
 			_, err = MediaAsset.AdminUploadInit(ctx, tenantID, userID, &tenant_dto.AdminMediaAssetUploadInitForm{
 				Type:          "video",
-				Variant:       "preview",
+				Variant:       &v,
 				SourceAssetID: &src.ID,
 			}, now)
 			So(err, ShouldNotBeNil)
@@ -106,4 +109,3 @@ func (s *MediaAssetTestSuite) Test_AdminUploadInit_VariantAndSource() {
 		})
 	})
 }
-
--- a/backend/app/services/media_delivery.go
+++ b/backend/app/services/media_delivery.go
@@ -12,7 +12,6 @@ import (

 	jwtlib "github.com/golang-jwt/jwt/v4"
 	log "github.com/sirupsen/logrus"
-	"go.ipao.vip/gen/types"
 	"gorm.io/gorm"
 )

@@ -126,10 +125,13 @@ func (s *mediaDelivery) ResolvePlayRedirect(ctx context.Context, tenantID int64,
 		"exp":            claims.ExpiresAt,
 	}).Info("services.media_delivery.resolve_play_redirect")

-	var asset models.MediaAsset
-	if err := _db.WithContext(ctx).
-		Where("tenant_id = ? AND id = ? AND deleted_at IS NULL", tenantID, claims.AssetID).
-		First(&asset).Error; err != nil {
+	tblAsset, queryAsset := models.MediaAssetQuery.QueryContext(ctx)
+	asset, err := queryAsset.Where(
+		tblAsset.TenantID.Eq(tenantID),
+		tblAsset.ID.Eq(claims.AssetID),
+		tblAsset.DeletedAt.IsNull(),
+	).First()
+	if err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return "", errorx.ErrRecordNotFound.WithMsg("media asset not found")
 		}
@@ -140,16 +142,13 @@ func (s *mediaDelivery) ResolvePlayRedirect(ctx context.Context, tenantID int64,
 	}

 	// 二次校验：token 必须对应“该内容 + 该角色”的绑定关系，避免 token 被滥用到非预期内容。
-	var ca models.ContentAsset
-	if err := _db.WithContext(ctx).
-		Where(
-			"tenant_id = ? AND content_id = ? AND asset_id = ? AND role = ?",
-			tenantID,
-			claims.ContentID,
-			claims.AssetID,
-			claims.Role,
-		).
-		First(&ca).Error; err != nil {
+	tblCA, queryCA := models.ContentAssetQuery.QueryContext(ctx)
+	if _, err := queryCA.Where(
+		tblCA.TenantID.Eq(tenantID),
+		tblCA.ContentID.Eq(claims.ContentID),
+		tblCA.AssetID.Eq(claims.AssetID),
+		tblCA.Role.Eq(claims.Role),
+	).First(); err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return "", errorx.ErrRecordNotFound.WithMsg("content asset binding not found")
 		}
@@ -162,7 +161,6 @@ func (s *mediaDelivery) ResolvePlayRedirect(ctx context.Context, tenantID int64,
 	case "stub":
 		return "", errorx.ErrServiceUnavailable.WithMsg("storage provider not configured")
 	default:
-		_ = types.JSON(asset.Meta) // keep meta referenced for future extensions
 		return "", errorx.ErrServiceUnavailable.WithMsg("storage provider not implemented: " + asset.Provider)
 	}
 }
--- a/backend/app/services/order.go
+++ b/backend/app/services/order.go
@@ -14,6 +14,7 @@ import (
 	"quyun/v2/app/http/tenant/dto"
 	"quyun/v2/app/requests"
 	"quyun/v2/database"
+	"quyun/v2/database/fields"
 	"quyun/v2/database/models"
 	"quyun/v2/pkg/consts"

@@ -28,6 +29,17 @@ import (
 	"go.ipao.vip/gen/types"
 )

+func newOrderSnapshot(kind consts.OrderType, payload any) types.JSONType[fields.OrdersSnapshot] {
+	b, err := json.Marshal(payload)
+	if err != nil || len(b) == 0 {
+		b = []byte("{}")
+	}
+	return types.NewJSONType(fields.OrdersSnapshot{
+		Kind: string(kind),
+		Data: b,
+	})
+}
+
 // AdminOrderExportCSV 租户管理员导出订单列表（CSV 文本）。
 func (s *order) AdminOrderExportCSV(ctx context.Context, tenantID int64, filter *dto.AdminOrderListFilter) (*dto.AdminOrderExportResponse, error) {
 	if tenantID <= 0 {
@@ -305,76 +317,6 @@ func (s *order) AdminBatchTopupUsers(
 	return out, nil
 }

-// PurchaseOrderSnapshot 为“内容购买订单”的下单快照（用于历史展示与争议审计）。
-type PurchaseOrderSnapshot struct {
-	// ContentID 内容ID。
-	ContentID int64 `json:"content_id"`
-	// ContentTitle 内容标题（下单时快照，避免事后改名影响历史订单展示）。
-	ContentTitle string `json:"content_title"`
-	// ContentUserID 内容作者用户ID（用于审计与后续分成扩展）。
-	ContentUserID int64 `json:"content_user_id"`
-	// ContentVisibility 下单时的可见性快照。
-	ContentVisibility consts.ContentVisibility `json:"content_visibility"`
-	// PreviewSeconds 下单时的试看秒数快照。
-	PreviewSeconds int32 `json:"preview_seconds"`
-	// PreviewDownloadable 下单时的试看是否可下载快照（当前固定为 false）。
-	PreviewDownloadable bool `json:"preview_downloadable"`
-	// Currency 币种：当前固定 CNY（金额单位为分）。
-	Currency consts.Currency `json:"currency"`
-	// PriceAmount 基础价格（分）。
-	PriceAmount int64 `json:"price_amount"`
-	// DiscountType 折扣类型（none/percent/amount）。
-	DiscountType consts.DiscountType `json:"discount_type"`
-	// DiscountValue 折扣值（percent=0-100；amount=分）。
-	DiscountValue int64 `json:"discount_value"`
-	// DiscountStartAt 折扣开始时间（可选）。
-	DiscountStartAt *time.Time `json:"discount_start_at,omitempty"`
-	// DiscountEndAt 折扣结束时间（可选）。
-	DiscountEndAt *time.Time `json:"discount_end_at,omitempty"`
-	// AmountOriginal 原价金额（分）。
-	AmountOriginal int64 `json:"amount_original"`
-	// AmountDiscount 优惠金额（分）。
-	AmountDiscount int64 `json:"amount_discount"`
-	// AmountPaid 实付金额（分）。
-	AmountPaid int64 `json:"amount_paid"`
-	// PurchaseAt 下单时间（逻辑时间）。
-	PurchaseAt time.Time `json:"purchase_at"`
-	// PurchaseIdempotency 幂等键（可选）。
-	PurchaseIdempotency string `json:"purchase_idempotency_key,omitempty"`
-	// PurchasePricingNotes 价格计算补充说明（可选，便于排查争议）。
-	PurchasePricingNotes string `json:"purchase_pricing_notes,omitempty"`
-}
-
-// OrderItemSnapshot 为“订单明细”的内容快照。
-type OrderItemSnapshot struct {
-	// ContentID 内容ID。
-	ContentID int64 `json:"content_id"`
-	// ContentTitle 内容标题快照。
-	ContentTitle string `json:"content_title"`
-	// ContentUserID 内容作者用户ID。
-	ContentUserID int64 `json:"content_user_id"`
-	// AmountPaid 该行实付金额（分）。
-	AmountPaid int64 `json:"amount_paid"`
-}
-
-// TopupOrderSnapshot 为“后台充值订单”的快照（用于审计与追责）。
-type TopupOrderSnapshot struct {
-	// OperatorUserID 充值操作人用户ID（租户管理员）。
-	OperatorUserID int64 `json:"operator_user_id"`
-	// TargetUserID 充值目标用户ID（租户成员）。
-	TargetUserID int64 `json:"target_user_id"`
-	// Amount 充值金额（分）。
-	Amount int64 `json:"amount"`
-	// Currency 币种：当前固定 CNY（金额单位为分）。
-	Currency consts.Currency `json:"currency"`
-	// Reason 充值原因（可选，强烈建议填写用于审计）。
-	Reason string `json:"reason,omitempty"`
-	// IdempotencyKey 幂等键（可选）。
-	IdempotencyKey string `json:"idempotency_key,omitempty"`
-	// TopupAt 充值时间（逻辑时间）。
-	TopupAt time.Time `json:"topup_at"`
-}
-
 // PurchaseContentParams 定义“租户内使用余额购买内容”的入参。
 type PurchaseContentParams struct {
 	// TenantID 租户 ID（多租户隔离范围）。
@@ -409,17 +351,6 @@ type order struct {
 	ledger *ledger
 }

-func marshalSnapshot(v any) types.JSON {
-	b, err := json.Marshal(v)
-	if err != nil {
-		return types.JSON([]byte("{}"))
-	}
-	if len(b) == 0 {
-		return types.JSON([]byte("{}"))
-	}
-	return types.JSON(b)
-}
-
 // AdminTopupUser 租户管理员给租户成员充值（增加该租户下的可用余额）。
 func (s *order) AdminTopupUser(
 	ctx context.Context,
@@ -475,7 +406,7 @@ func (s *order) AdminTopupUser(
 		}

 		// 先落订单（paid），再写入账本（credit_topup），确保“订单可追溯 + 账本可对账”。
-		snapshot := marshalSnapshot(&TopupOrderSnapshot{
+		snapshot := newOrderSnapshot(consts.OrderTypeTopup, &fields.OrdersTopupSnapshot{
 			OperatorUserID: operatorUserID,
 			TargetUserID:   targetUserID,
 			Amount:         amount,
@@ -1061,7 +992,7 @@ func (s *order) PurchaseContent(ctx context.Context, params *PurchaseContentPara
 			discountEndAt = &t
 		}

-		purchaseSnapshot := marshalSnapshot(&PurchaseOrderSnapshot{
+		purchaseSnapshot := newOrderSnapshot(consts.OrderTypeContentPurchase, &fields.OrdersContentPurchaseSnapshot{
 			ContentID:           content.ID,
 			ContentTitle:        content.Title,
 			ContentUserID:       content.UserID,
@@ -1080,7 +1011,7 @@ func (s *order) PurchaseContent(ctx context.Context, params *PurchaseContentPara
 			PurchaseAt:          now,
 			PurchaseIdempotency: params.IdempotencyKey,
 		})
-		itemSnapshot := marshalSnapshot(&OrderItemSnapshot{
+		itemSnapshot := types.NewJSONType(fields.OrderItemsSnapshot{
 			ContentID:     content.ID,
 			ContentTitle:  content.Title,
 			ContentUserID: content.UserID,
@@ -1303,7 +1234,7 @@ func (s *order) PurchaseContent(ctx context.Context, params *PurchaseContentPara
 			t := price.DiscountEndAt
 			discountEndAt = &t
 		}
-		purchaseSnapshot := marshalSnapshot(&PurchaseOrderSnapshot{
+		purchaseSnapshot := newOrderSnapshot(consts.OrderTypeContentPurchase, &fields.OrdersContentPurchaseSnapshot{
 			ContentID:           content.ID,
 			ContentTitle:        content.Title,
 			ContentUserID:       content.UserID,
@@ -1321,7 +1252,7 @@ func (s *order) PurchaseContent(ctx context.Context, params *PurchaseContentPara
 			AmountPaid:          amountPaid,
 			PurchaseAt:          now,
 		})
-		itemSnapshot := marshalSnapshot(&OrderItemSnapshot{
+		itemSnapshot := types.NewJSONType(fields.OrderItemsSnapshot{
 			ContentID:     content.ID,
 			ContentTitle:  content.Title,
 			ContentUserID: content.UserID,
--- a/backend/app/services/order_test.go
+++ b/backend/app/services/order_test.go
@@ -14,6 +14,7 @@ import (
 	"quyun/v2/app/http/tenant/dto"
 	"quyun/v2/app/requests"
 	"quyun/v2/database"
+	"quyun/v2/database/fields"
 	"quyun/v2/database/models"
 	"quyun/v2/pkg/consts"

@@ -27,6 +28,13 @@ import (
 	"go.uber.org/dig"
 )

+func newLegacyOrderSnapshot() types.JSONType[fields.OrdersSnapshot] {
+	return types.NewJSONType(fields.OrdersSnapshot{
+		Kind: "legacy",
+		Data: json.RawMessage([]byte("{}")),
+	})
+}
+
 type OrderTestSuiteInjectParams struct {
 	dig.In

@@ -144,11 +152,14 @@ func (s *OrderTestSuite) Test_AdminTopupUser() {
 			So(orderModel.Status, ShouldEqual, consts.OrderStatusPaid)
 			So(orderModel.AmountPaid, ShouldEqual, 300)

-			var snap map[string]any
-			So(json.Unmarshal([]byte(orderModel.Snapshot), &snap), ShouldBeNil)
-			So(snap["operator_user_id"], ShouldEqual, float64(operatorUserID))
-			So(snap["target_user_id"], ShouldEqual, float64(targetUserID))
-			So(snap["amount"], ShouldEqual, float64(300))
+				snap := orderModel.Snapshot.Data()
+				So(snap.Kind, ShouldEqual, string(consts.OrderTypeTopup))
+
+				var snapData fields.OrdersTopupSnapshot
+				So(json.Unmarshal(snap.Data, &snapData), ShouldBeNil)
+				So(snapData.OperatorUserID, ShouldEqual, operatorUserID)
+				So(snapData.TargetUserID, ShouldEqual, targetUserID)
+				So(snapData.Amount, ShouldEqual, int64(300))

 			var tu models.TenantUser
 			So(_db.WithContext(ctx).Where("tenant_id = ? AND user_id = ?", tenantID, targetUserID).First(&tu).Error, ShouldBeNil)
@@ -211,7 +222,7 @@ func (s *OrderTestSuite) Test_MyOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -224,7 +235,7 @@ func (s *OrderTestSuite) Test_MyOrderPage() {
 				ContentID:     111,
 				ContentUserID: 1,
 				AmountPaid:    100,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -236,7 +247,7 @@ func (s *OrderTestSuite) Test_MyOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 200,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now.Add(time.Minute),
 				CreatedAt:  now.Add(time.Minute),
 				UpdatedAt:  now.Add(time.Minute),
@@ -249,7 +260,7 @@ func (s *OrderTestSuite) Test_MyOrderPage() {
 				ContentID:     222,
 				ContentUserID: 1,
 				AmountPaid:    200,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now.Add(time.Minute),
 				UpdatedAt:     now.Add(time.Minute),
 			}).Create(ctx), ShouldBeNil)
@@ -310,7 +321,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now.Add(-time.Hour),
 				CreatedAt:  now.Add(-time.Hour),
 				UpdatedAt:  now.Add(-time.Hour),
@@ -323,7 +334,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     333,
 				ContentUserID: 1,
 				AmountPaid:    100,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now.Add(-time.Hour),
 				UpdatedAt:     now.Add(-time.Hour),
 			}).Create(ctx), ShouldBeNil)
@@ -335,7 +346,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 200,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -348,7 +359,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     444,
 				ContentUserID: 1,
 				AmountPaid:    200,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -373,7 +384,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -386,7 +397,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     555,
 				ContentUserID: 1,
 				AmountPaid:    100,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -429,7 +440,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -442,7 +453,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -499,7 +510,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -512,7 +523,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     c1.ID,
 				ContentUserID: 1,
 				AmountPaid:    100,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -524,7 +535,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -537,7 +548,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     c2.ID,
 				ContentUserID: 1,
 				AmountPaid:    100,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -560,7 +571,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now.Add(-time.Hour),
 				UpdatedAt:  now.Add(-time.Hour),
@@ -574,7 +585,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 200,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -601,7 +612,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 500,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now.Add(-time.Hour),
 				UpdatedAt:  now.Add(-time.Hour),
@@ -615,7 +626,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -653,7 +664,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 100,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -667,7 +678,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 200,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -697,7 +708,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 500,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -710,7 +721,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     contentID,
 				ContentUserID: 1,
 				AmountPaid:    500,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -723,7 +734,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 50,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -736,7 +747,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     contentID,
 				ContentUserID: 1,
 				AmountPaid:    50,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -749,7 +760,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusCreated,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 500,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -762,7 +773,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     contentID,
 				ContentUserID: 1,
 				AmountPaid:    500,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -775,7 +786,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 500,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -788,7 +799,7 @@ func (s *OrderTestSuite) Test_AdminOrderPage() {
 				ContentID:     contentID,
 				ContentUserID: 1,
 				AmountPaid:    500,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}).Create(ctx), ShouldBeNil)
@@ -859,7 +870,7 @@ func (s *OrderTestSuite) Test_AdminOrderExportCSV() {
 				Status:     consts.OrderStatusPaid,
 				Currency:   consts.CurrencyCNY,
 				AmountPaid: 123,
-				Snapshot:   types.JSON([]byte("{}")),
+				Snapshot:   newLegacyOrderSnapshot(),
 				PaidAt:     now,
 				CreatedAt:  now,
 				UpdatedAt:  now,
@@ -1028,7 +1039,7 @@ func (s *OrderTestSuite) Test_AdminRefundOrder() {
 				AmountOriginal: 100,
 				AmountDiscount: 0,
 				AmountPaid:     100,
-				Snapshot:       types.JSON([]byte("{}")),
+				Snapshot:       newLegacyOrderSnapshot(),
 				PaidAt:         now,
 				CreatedAt:      now,
 				UpdatedAt:      now,
@@ -1055,7 +1066,7 @@ func (s *OrderTestSuite) Test_AdminRefundOrder() {
 				AmountOriginal: 100,
 				AmountDiscount: 0,
 				AmountPaid:     100,
-				Snapshot:       types.JSON([]byte("{}")),
+				Snapshot:       newLegacyOrderSnapshot(),
 				PaidAt:         now.Add(-consts.DefaultOrderRefundWindow).Add(-time.Second),
 				CreatedAt:      now,
 				UpdatedAt:      now,
@@ -1079,7 +1090,7 @@ func (s *OrderTestSuite) Test_AdminRefundOrder() {
 				AmountOriginal: 300,
 				AmountDiscount: 0,
 				AmountPaid:     300,
-				Snapshot:       types.JSON([]byte("{}")),
+				Snapshot:       newLegacyOrderSnapshot(),
 				PaidAt:         now,
 				CreatedAt:      now,
 				UpdatedAt:      now,
@@ -1093,7 +1104,7 @@ func (s *OrderTestSuite) Test_AdminRefundOrder() {
 				ContentID:     contentID,
 				ContentUserID: 999,
 				AmountPaid:    300,
-				Snapshot:      types.JSON([]byte("{}")),
+				Snapshot:      types.NewJSONType(fields.OrderItemsSnapshot{}),
 				CreatedAt:     now,
 				UpdatedAt:     now,
 			}
@@ -1217,11 +1228,14 @@ func (s *OrderTestSuite) Test_PurchaseContent() {
 			So(res1.Access, ShouldNotBeNil)
 			So(res1.Access.Status, ShouldEqual, consts.ContentAccessStatusActive)

-			var snap map[string]any
-			So(json.Unmarshal([]byte(res1.Order.Snapshot), &snap), ShouldBeNil)
-			So(snap["content_id"], ShouldEqual, float64(content.ID))
-			So(snap["content_title"], ShouldEqual, content.Title)
-			So(snap["amount_paid"], ShouldEqual, float64(0))
+			snap := res1.Order.Snapshot.Data()
+			So(snap.Kind, ShouldEqual, string(consts.OrderTypeContentPurchase))
+
+			var snapData fields.OrdersContentPurchaseSnapshot
+			So(json.Unmarshal(snap.Data, &snapData), ShouldBeNil)
+			So(snapData.ContentID, ShouldEqual, content.ID)
+			So(snapData.ContentTitle, ShouldEqual, content.Title)
+			So(snapData.AmountPaid, ShouldEqual, int64(0))

 			res2, err := Order.PurchaseContent(ctx, &PurchaseContentParams{
 				TenantID:       tenantID,
@@ -1264,16 +1278,18 @@ func (s *OrderTestSuite) Test_PurchaseContent() {
 			So(res1.Access, ShouldNotBeNil)
 			So(res1.Access.Status, ShouldEqual, consts.ContentAccessStatusActive)

-			var snap map[string]any
-			So(json.Unmarshal([]byte(res1.Order.Snapshot), &snap), ShouldBeNil)
-			So(snap["content_id"], ShouldEqual, float64(content.ID))
-			So(snap["amount_paid"], ShouldEqual, float64(300))
-			So(snap["amount_original"], ShouldEqual, float64(300))
+			snap := res1.Order.Snapshot.Data()
+			So(snap.Kind, ShouldEqual, string(consts.OrderTypeContentPurchase))

-			var itemSnap map[string]any
-			So(json.Unmarshal([]byte(res1.OrderItem.Snapshot), &itemSnap), ShouldBeNil)
-			So(itemSnap["content_id"], ShouldEqual, float64(content.ID))
-			So(itemSnap["amount_paid"], ShouldEqual, float64(300))
+			var snapData fields.OrdersContentPurchaseSnapshot
+			So(json.Unmarshal(snap.Data, &snapData), ShouldBeNil)
+			So(snapData.ContentID, ShouldEqual, content.ID)
+			So(snapData.AmountPaid, ShouldEqual, int64(300))
+			So(snapData.AmountOriginal, ShouldEqual, int64(300))
+
+			itemSnap := res1.OrderItem.Snapshot.Data()
+			So(itemSnap.ContentID, ShouldEqual, content.ID)
+			So(itemSnap.AmountPaid, ShouldEqual, int64(300))

 			var tu models.TenantUser
 			So(_db.WithContext(ctx).Where("tenant_id = ? AND user_id = ?", tenantID, buyerUserID).First(&tu).Error, ShouldBeNil)
--- a/backend/database/.transform.yaml
+++ b/backend/database/.transform.yaml
@@ -9,6 +9,7 @@ ignores:
 imports:
  - go.ipao.vip/gen
  - quyun/v2/pkg/consts
+  - quyun/v2/database/fields
 field_type:
  users:
    roles: types.Array[consts.Role]
@@ -22,6 +23,7 @@ field_type:
  media_assets:
    type: consts.MediaAssetType
    status: consts.MediaAssetStatus
+    variant: consts.MediaAssetVariant
  contents:
    status: consts.ContentStatus
    visibility: consts.ContentVisibility
@@ -36,6 +38,9 @@ field_type:
    type: consts.OrderType
    status: consts.OrderStatus
    currency: consts.Currency
+    snapshot: types.JSONType[fields.OrdersSnapshot]
+  order_items:
+    snapshot: types.JSONType[fields.OrderItemsSnapshot]
  tenant_ledgers:
    type: consts.TenantLedgerType
  tenant_invites:
--- a/backend/database/fields/order_items.go
+++ b/backend/database/fields/order_items.go
@@ -0,0 +1,15 @@
+package fields
+
+// OrderItemsSnapshot 定义 order_items.snapshot 的固定结构。
+//
+// 该快照用于“历史展示与审计”：即使内容标题/作者等信息后续变更，也不影响已下单记录的展示一致性。
+type OrderItemsSnapshot struct {
+	// ContentID 内容 ID。
+	ContentID int64 `json:"content_id"`
+	// ContentTitle 内容标题快照。
+	ContentTitle string `json:"content_title"`
+	// ContentUserID 内容作者用户 ID。
+	ContentUserID int64 `json:"content_user_id"`
+	// AmountPaid 该行实付金额（分）。
+	AmountPaid int64 `json:"amount_paid"`
+}
--- a/backend/database/fields/orders.go
+++ b/backend/database/fields/orders.go
@@ -0,0 +1,98 @@
+package fields
+
+import (
+	"encoding/json"
+	"time"
+
+	"quyun/v2/pkg/consts"
+)
+
+// OrdersSnapshot 是 orders.snapshot 的统一包裹结构（判别联合）。
+//
+// 设计目标：
+// - 同一字段支持多种快照结构（按 kind 区分）。
+// - 查询/展示时可以先看 kind，再按需解析 data。
+// - 兼容历史数据：如果旧数据没有 kind/data，则按 legacy 处理（data = 原始 JSON）。
+type OrdersSnapshot struct {
+	// Kind 快照类型：建议与订单类型对齐（例如 content_purchase / topup）。
+	Kind string `json:"kind"`
+	// Data 具体快照数据（按 Kind 对应不同结构）。
+	Data json.RawMessage `json:"data"`
+}
+
+type ordersSnapshotWire struct {
+	Kind string          `json:"kind"`
+	Data json.RawMessage `json:"data"`
+}
+
+func (s *OrdersSnapshot) UnmarshalJSON(b []byte) error {
+	var w ordersSnapshotWire
+	if err := json.Unmarshal(b, &w); err == nil && (w.Kind != "" || w.Data != nil) {
+		s.Kind = w.Kind
+		s.Data = w.Data
+		return nil
+	}
+
+	// 兼容旧结构：旧 snapshot 通常是一个扁平对象（没有 kind/data）。
+	s.Kind = "legacy"
+	s.Data = append(s.Data[:0], b...)
+	return nil
+}
+
+// OrdersContentPurchaseSnapshot 为“内容购买订单”的下单快照（用于历史展示与争议审计）。
+type OrdersContentPurchaseSnapshot struct {
+	// ContentID 内容ID。
+	ContentID int64 `json:"content_id"`
+	// ContentTitle 内容标题（下单时快照，避免事后改名影响历史订单展示）。
+	ContentTitle string `json:"content_title"`
+	// ContentUserID 内容作者用户ID（用于审计与后续分成扩展）。
+	ContentUserID int64 `json:"content_user_id"`
+	// ContentVisibility 下单时的可见性快照。
+	ContentVisibility consts.ContentVisibility `json:"content_visibility"`
+	// PreviewSeconds 下单时的试看秒数快照。
+	PreviewSeconds int32 `json:"preview_seconds"`
+	// PreviewDownloadable 下单时的试看是否可下载快照（当前固定为 false）。
+	PreviewDownloadable bool `json:"preview_downloadable"`
+	// Currency 币种：当前固定 CNY（金额单位为分）。
+	Currency consts.Currency `json:"currency"`
+	// PriceAmount 基础价格（分）。
+	PriceAmount int64 `json:"price_amount"`
+	// DiscountType 折扣类型（none/percent/amount）。
+	DiscountType consts.DiscountType `json:"discount_type"`
+	// DiscountValue 折扣值（percent=0-100；amount=分）。
+	DiscountValue int64 `json:"discount_value"`
+	// DiscountStartAt 折扣开始时间（可选）。
+	DiscountStartAt *time.Time `json:"discount_start_at,omitempty"`
+	// DiscountEndAt 折扣结束时间（可选）。
+	DiscountEndAt *time.Time `json:"discount_end_at,omitempty"`
+	// AmountOriginal 原价金额（分）。
+	AmountOriginal int64 `json:"amount_original"`
+	// AmountDiscount 优惠金额（分）。
+	AmountDiscount int64 `json:"amount_discount"`
+	// AmountPaid 实付金额（分）。
+	AmountPaid int64 `json:"amount_paid"`
+	// PurchaseAt 下单时间（逻辑时间）。
+	PurchaseAt time.Time `json:"purchase_at"`
+	// PurchaseIdempotency 幂等键（可选）。
+	PurchaseIdempotency string `json:"purchase_idempotency_key,omitempty"`
+	// PurchasePricingNotes 价格计算补充说明（可选，便于排查争议）。
+	PurchasePricingNotes string `json:"purchase_pricing_notes,omitempty"`
+}
+
+// OrdersTopupSnapshot 为“后台充值订单”的快照（用于审计与追责）。
+type OrdersTopupSnapshot struct {
+	// OperatorUserID 充值操作人用户ID（租户管理员）。
+	OperatorUserID int64 `json:"operator_user_id"`
+	// TargetUserID 充值目标用户ID（租户成员）。
+	TargetUserID int64 `json:"target_user_id"`
+	// Amount 充值金额（分）。
+	Amount int64 `json:"amount"`
+	// Currency 币种：当前固定 CNY（金额单位为分）。
+	Currency consts.Currency `json:"currency"`
+	// Reason 充值原因（可选，强烈建议填写用于审计）。
+	Reason string `json:"reason,omitempty"`
+	// IdempotencyKey 幂等键（可选）。
+	IdempotencyKey string `json:"idempotency_key,omitempty"`
+	// TopupAt 充值时间（逻辑时间）。
+	TopupAt time.Time `json:"topup_at"`
+}
--- a/backend/database/migrations/20251222174000_media_assets_variant.sql
+++ b/backend/database/migrations/20251222174000_media_assets_variant.sql
@@ -9,9 +9,19 @@ SET variant = 'main'
 WHERE variant IS NULL OR variant = '';

 -- 约束：只允许 main/preview
-ALTER TABLE media_assets
-    ADD CONSTRAINT IF NOT EXISTS ck_media_assets_variant
-        CHECK (variant IN ('main', 'preview'));
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1
+        FROM pg_constraint
+        WHERE conname = 'ck_media_assets_variant'
+    ) THEN
+        ALTER TABLE media_assets
+            ADD CONSTRAINT ck_media_assets_variant
+                CHECK (variant IN ('main', 'preview'));
+    END IF;
+END
+$$;

 COMMENT ON COLUMN media_assets.variant IS '产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过';

@@ -24,4 +34,3 @@ DROP INDEX IF EXISTS ix_media_assets_tenant_variant;
 ALTER TABLE media_assets DROP CONSTRAINT IF EXISTS ck_media_assets_variant;
 ALTER TABLE media_assets DROP COLUMN IF EXISTS variant;
 -- +goose StatementEnd
-
--- a/backend/database/models/media_assets.gen.go
+++ b/backend/database/models/media_assets.gen.go
@@ -19,18 +19,20 @@ const TableNameMediaAsset = "media_assets"

 // MediaAsset mapped from table <media_assets>
 type MediaAsset struct {
-	ID        int64                   `gorm:"column:id;type:bigint;primaryKey;autoIncrement:true;comment:主键ID：自增；仅用于内部关联" json:"id"`                                                                    // 主键ID：自增；仅用于内部关联
-	TenantID  int64                   `gorm:"column:tenant_id;type:bigint;not null;comment:租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id" json:"tenant_id"`                                                      // 租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id
-	UserID    int64                   `gorm:"column:user_id;type:bigint;not null;comment:用户ID：资源上传者；用于审计与权限控制" json:"user_id"`                                                                          // 用户ID：资源上传者；用于审计与权限控制
-	Type      consts.MediaAssetType   `gorm:"column:type;type:character varying(32);not null;default:video;comment:资源类型：video/audio/image；决定后续处理流程（转码/缩略图/封面等）" json:"type"`                            // 资源类型：video/audio/image；决定后续处理流程（转码/缩略图/封面等）
-	Status    consts.MediaAssetStatus `gorm:"column:status;type:character varying(32);not null;default:uploaded;comment:处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供" json:"status"` // 处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供
-	Provider  string                  `gorm:"column:provider;type:character varying(64);not null;comment:存储提供方：例如 s3/minio/oss；便于多存储扩展" json:"provider"`                                                // 存储提供方：例如 s3/minio/oss；便于多存储扩展
-	Bucket    string                  `gorm:"column:bucket;type:character varying(128);not null;comment:存储桶：对象所在 bucket；与 provider 组合确定存储定位" json:"bucket"`                                             // 存储桶：对象所在 bucket；与 provider 组合确定存储定位
-	ObjectKey string                  `gorm:"column:object_key;type:character varying(512);not null;comment:对象键：对象在 bucket 内的 key；不得暴露可长期复用的直链（通过签名URL/token下发）" json:"object_key"`                     // 对象键：对象在 bucket 内的 key；不得暴露可长期复用的直链（通过签名URL/token下发）
-	Meta      types.JSON              `gorm:"column:meta;type:jsonb;not null;default:{};comment:元数据：JSON；包含 hash、duration、width、height、bitrate、codec 等；用于展示与计费/风控" json:"meta"`                         // 元数据：JSON；包含 hash、duration、width、height、bitrate、codec 等；用于展示与计费/风控
-	DeletedAt gorm.DeletedAt          `gorm:"column:deleted_at;type:timestamp with time zone;comment:软删除时间：非空表示已删除；对外接口需过滤" json:"deleted_at"`                                                          // 软删除时间：非空表示已删除；对外接口需过滤
-	CreatedAt time.Time               `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()；用于审计与排序" json:"created_at"`                                   // 创建时间：默认 now()；用于审计与排序
-	UpdatedAt time.Time               `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()；更新状态/元数据时写入" json:"updated_at"`                               // 更新时间：默认 now()；更新状态/元数据时写入
+	ID            int64                    `gorm:"column:id;type:bigint;primaryKey;autoIncrement:true;comment:主键ID：自增；仅用于内部关联" json:"id"`                                                                    // 主键ID：自增；仅用于内部关联
+	TenantID      int64                    `gorm:"column:tenant_id;type:bigint;not null;comment:租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id" json:"tenant_id"`                                                      // 租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id
+	UserID        int64                    `gorm:"column:user_id;type:bigint;not null;comment:用户ID：资源上传者；用于审计与权限控制" json:"user_id"`                                                                          // 用户ID：资源上传者；用于审计与权限控制
+	Type          consts.MediaAssetType    `gorm:"column:type;type:character varying(32);not null;default:video;comment:资源类型：video/audio/image；决定后续处理流程（转码/缩略图/封面等）" json:"type"`                            // 资源类型：video/audio/image；决定后续处理流程（转码/缩略图/封面等）
+	Status        consts.MediaAssetStatus  `gorm:"column:status;type:character varying(32);not null;default:uploaded;comment:处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供" json:"status"` // 处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供
+	Provider      string                   `gorm:"column:provider;type:character varying(64);not null;comment:存储提供方：例如 s3/minio/oss；便于多存储扩展" json:"provider"`                                                // 存储提供方：例如 s3/minio/oss；便于多存储扩展
+	Bucket        string                   `gorm:"column:bucket;type:character varying(128);not null;comment:存储桶：对象所在 bucket；与 provider 组合确定存储定位" json:"bucket"`                                             // 存储桶：对象所在 bucket；与 provider 组合确定存储定位
+	ObjectKey     string                   `gorm:"column:object_key;type:character varying(512);not null;comment:对象键：对象在 bucket 内的 key；不得暴露可长期复用的直链（通过签名URL/token下发）" json:"object_key"`                     // 对象键：对象在 bucket 内的 key；不得暴露可长期复用的直链（通过签名URL/token下发）
+	Meta          types.JSON               `gorm:"column:meta;type:jsonb;not null;default:{};comment:元数据：JSON；包含 hash、duration、width、height、bitrate、codec 等；用于展示与计费/风控" json:"meta"`                         // 元数据：JSON；包含 hash、duration、width、height、bitrate、codec 等；用于展示与计费/风控
+	DeletedAt     gorm.DeletedAt           `gorm:"column:deleted_at;type:timestamp with time zone;comment:软删除时间：非空表示已删除；对外接口需过滤" json:"deleted_at"`                                                          // 软删除时间：非空表示已删除；对外接口需过滤
+	CreatedAt     time.Time                `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()；用于审计与排序" json:"created_at"`                                   // 创建时间：默认 now()；用于审计与排序
+	UpdatedAt     time.Time                `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()；更新状态/元数据时写入" json:"updated_at"`                               // 更新时间：默认 now()；更新状态/元数据时写入
+	Variant       consts.MediaAssetVariant `gorm:"column:variant;type:character varying(32);not null;default:main;comment:产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过" json:"variant"`                        // 产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过
+	SourceAssetID int64                    `gorm:"column:source_asset_id;type:bigint;comment:派生来源资源ID：preview 产物可指向对应 main 资源；用于建立 preview/main 的 1:1 追溯关系" json:"source_asset_id"`                          // 派生来源资源ID：preview 产物可指向对应 main 资源；用于建立 preview/main 的 1:1 追溯关系
 }

 // Quick operations without importing query package
--- a/backend/database/models/media_assets.query.gen.go
+++ b/backend/database/models/media_assets.query.gen.go
@@ -37,6 +37,8 @@ func newMediaAsset(db *gorm.DB, opts ...gen.DOOption) mediaAssetQuery {
 	_mediaAssetQuery.DeletedAt = field.NewField(tableName, "deleted_at")
 	_mediaAssetQuery.CreatedAt = field.NewTime(tableName, "created_at")
 	_mediaAssetQuery.UpdatedAt = field.NewTime(tableName, "updated_at")
+	_mediaAssetQuery.Variant = field.NewField(tableName, "variant")
+	_mediaAssetQuery.SourceAssetID = field.NewInt64(tableName, "source_asset_id")

 	_mediaAssetQuery.fillFieldMap()

@@ -46,19 +48,21 @@ func newMediaAsset(db *gorm.DB, opts ...gen.DOOption) mediaAssetQuery {
 type mediaAssetQuery struct {
 	mediaAssetQueryDo mediaAssetQueryDo

-	ALL       field.Asterisk
-	ID        field.Int64  // 主键ID：自增；仅用于内部关联
-	TenantID  field.Int64  // 租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id
-	UserID    field.Int64  // 用户ID：资源上传者；用于审计与权限控制
-	Type      field.Field  // 资源类型：video/audio/image；决定后续处理流程（转码/缩略图/封面等）
-	Status    field.Field  // 处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供
-	Provider  field.String // 存储提供方：例如 s3/minio/oss；便于多存储扩展
-	Bucket    field.String // 存储桶：对象所在 bucket；与 provider 组合确定存储定位
-	ObjectKey field.String // 对象键：对象在 bucket 内的 key；不得暴露可长期复用的直链（通过签名URL/token下发）
-	Meta      field.JSONB  // 元数据：JSON；包含 hash、duration、width、height、bitrate、codec 等；用于展示与计费/风控
-	DeletedAt field.Field  // 软删除时间：非空表示已删除；对外接口需过滤
-	CreatedAt field.Time   // 创建时间：默认 now()；用于审计与排序
-	UpdatedAt field.Time   // 更新时间：默认 now()；更新状态/元数据时写入
+	ALL           field.Asterisk
+	ID            field.Int64  // 主键ID：自增；仅用于内部关联
+	TenantID      field.Int64  // 租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id
+	UserID        field.Int64  // 用户ID：资源上传者；用于审计与权限控制
+	Type          field.Field  // 资源类型：video/audio/image；决定后续处理流程（转码/缩略图/封面等）
+	Status        field.Field  // 处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供
+	Provider      field.String // 存储提供方：例如 s3/minio/oss；便于多存储扩展
+	Bucket        field.String // 存储桶：对象所在 bucket；与 provider 组合确定存储定位
+	ObjectKey     field.String // 对象键：对象在 bucket 内的 key；不得暴露可长期复用的直链（通过签名URL/token下发）
+	Meta          field.JSONB  // 元数据：JSON；包含 hash、duration、width、height、bitrate、codec 等；用于展示与计费/风控
+	DeletedAt     field.Field  // 软删除时间：非空表示已删除；对外接口需过滤
+	CreatedAt     field.Time   // 创建时间：默认 now()；用于审计与排序
+	UpdatedAt     field.Time   // 更新时间：默认 now()；更新状态/元数据时写入
+	Variant       field.Field  // 产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过
+	SourceAssetID field.Int64  // 派生来源资源ID：preview 产物可指向对应 main 资源；用于建立 preview/main 的 1:1 追溯关系

 	fieldMap map[string]field.Expr
 }
@@ -87,6 +91,8 @@ func (m *mediaAssetQuery) updateTableName(table string) *mediaAssetQuery {
 	m.DeletedAt = field.NewField(table, "deleted_at")
 	m.CreatedAt = field.NewTime(table, "created_at")
 	m.UpdatedAt = field.NewTime(table, "updated_at")
+	m.Variant = field.NewField(table, "variant")
+	m.SourceAssetID = field.NewInt64(table, "source_asset_id")

 	m.fillFieldMap()

@@ -119,7 +125,7 @@ func (m *mediaAssetQuery) GetFieldByName(fieldName string) (field.OrderExpr, boo
 }

 func (m *mediaAssetQuery) fillFieldMap() {
-	m.fieldMap = make(map[string]field.Expr, 12)
+	m.fieldMap = make(map[string]field.Expr, 14)
 	m.fieldMap["id"] = m.ID
 	m.fieldMap["tenant_id"] = m.TenantID
 	m.fieldMap["user_id"] = m.UserID
@@ -132,6 +138,8 @@ func (m *mediaAssetQuery) fillFieldMap() {
 	m.fieldMap["deleted_at"] = m.DeletedAt
 	m.fieldMap["created_at"] = m.CreatedAt
 	m.fieldMap["updated_at"] = m.UpdatedAt
+	m.fieldMap["variant"] = m.Variant
+	m.fieldMap["source_asset_id"] = m.SourceAssetID
 }

 func (m mediaAssetQuery) clone(db *gorm.DB) mediaAssetQuery {
--- a/backend/database/models/order_items.gen.go
+++ b/backend/database/models/order_items.gen.go
@@ -8,6 +8,8 @@ import (
 	"context"
 	"time"

+	"quyun/v2/database/fields"
+
 	"go.ipao.vip/gen"
 	"go.ipao.vip/gen/types"
 )
@@ -16,18 +18,18 @@ const TableNameOrderItem = "order_items"

 // OrderItem mapped from table <order_items>
 type OrderItem struct {
-	ID            int64      `gorm:"column:id;type:bigint;primaryKey;autoIncrement:true;comment:主键ID：自增" json:"id"`                                          // 主键ID：自增
-	TenantID      int64      `gorm:"column:tenant_id;type:bigint;not null;comment:租户ID：多租户隔离关键字段；必须与 orders.tenant_id 一致" json:"tenant_id"`                  // 租户ID：多租户隔离关键字段；必须与 orders.tenant_id 一致
-	UserID        int64      `gorm:"column:user_id;type:bigint;not null;comment:用户ID：下单用户（buyer）；冗余字段用于查询加速与审计" json:"user_id"`                              // 用户ID：下单用户（buyer）；冗余字段用于查询加速与审计
-	OrderID       int64      `gorm:"column:order_id;type:bigint;not null;comment:订单ID：关联 orders.id；用于聚合订单明细" json:"order_id"`                                // 订单ID：关联 orders.id；用于聚合订单明细
-	ContentID     int64      `gorm:"column:content_id;type:bigint;not null;comment:内容ID：关联 contents.id；用于生成/撤销 content_access" json:"content_id"`            // 内容ID：关联 contents.id；用于生成/撤销 content_access
-	ContentUserID int64      `gorm:"column:content_user_id;type:bigint;not null;comment:内容作者用户ID：用于后续分成/对账扩展；当前可为 0 或写入内容创建者" json:"content_user_id"`        // 内容作者用户ID：用于后续分成/对账扩展；当前可为 0 或写入内容创建者
-	AmountPaid    int64      `gorm:"column:amount_paid;type:bigint;not null;comment:该行实付金额：分；通常等于订单 amount_paid（单内容场景）" json:"amount_paid"`                  // 该行实付金额：分；通常等于订单 amount_paid（单内容场景）
-	Snapshot      types.JSON `gorm:"column:snapshot;type:jsonb;not null;default:{};comment:内容快照：JSON；建议包含 title/price/discount 等，用于历史展示与审计" json:"snapshot"` // 内容快照：JSON；建议包含 title/price/discount 等，用于历史展示与审计
-	CreatedAt     time.Time  `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()" json:"created_at"`         // 创建时间：默认 now()
-	UpdatedAt     time.Time  `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()" json:"updated_at"`         // 更新时间：默认 now()
-	Order         *Order     `gorm:"foreignKey:OrderID;references:ID" json:"order,omitempty"`
-	Content       *Content   `gorm:"foreignKey:ContentID;references:ID" json:"content,omitempty"`
+	ID            int64                                     `gorm:"column:id;type:bigint;primaryKey;autoIncrement:true;comment:主键ID：自增" json:"id"`                                          // 主键ID：自增
+	TenantID      int64                                     `gorm:"column:tenant_id;type:bigint;not null;comment:租户ID：多租户隔离关键字段；必须与 orders.tenant_id 一致" json:"tenant_id"`                  // 租户ID：多租户隔离关键字段；必须与 orders.tenant_id 一致
+	UserID        int64                                     `gorm:"column:user_id;type:bigint;not null;comment:用户ID：下单用户（buyer）；冗余字段用于查询加速与审计" json:"user_id"`                              // 用户ID：下单用户（buyer）；冗余字段用于查询加速与审计
+	OrderID       int64                                     `gorm:"column:order_id;type:bigint;not null;comment:订单ID：关联 orders.id；用于聚合订单明细" json:"order_id"`                                // 订单ID：关联 orders.id；用于聚合订单明细
+	ContentID     int64                                     `gorm:"column:content_id;type:bigint;not null;comment:内容ID：关联 contents.id；用于生成/撤销 content_access" json:"content_id"`            // 内容ID：关联 contents.id；用于生成/撤销 content_access
+	ContentUserID int64                                     `gorm:"column:content_user_id;type:bigint;not null;comment:内容作者用户ID：用于后续分成/对账扩展；当前可为 0 或写入内容创建者" json:"content_user_id"`        // 内容作者用户ID：用于后续分成/对账扩展；当前可为 0 或写入内容创建者
+	AmountPaid    int64                                     `gorm:"column:amount_paid;type:bigint;not null;comment:该行实付金额：分；通常等于订单 amount_paid（单内容场景）" json:"amount_paid"`                  // 该行实付金额：分；通常等于订单 amount_paid（单内容场景）
+	Snapshot      types.JSONType[fields.OrderItemsSnapshot] `gorm:"column:snapshot;type:jsonb;not null;default:{};comment:内容快照：JSON；建议包含 title/price/discount 等，用于历史展示与审计" json:"snapshot"` // 内容快照：JSON；建议包含 title/price/discount 等，用于历史展示与审计
+	CreatedAt     time.Time                                 `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()" json:"created_at"`         // 创建时间：默认 now()
+	UpdatedAt     time.Time                                 `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()" json:"updated_at"`         // 更新时间：默认 now()
+	Order         *Order                                    `gorm:"foreignKey:OrderID;references:ID" json:"order,omitempty"`
+	Content       *Content                                  `gorm:"foreignKey:ContentID;references:ID" json:"content,omitempty"`
 }

 // Quick operations without importing query package
--- a/backend/database/models/orders.gen.go
+++ b/backend/database/models/orders.gen.go
@@ -8,6 +8,7 @@ import (
 	"context"
 	"time"

+	"quyun/v2/database/fields"
 	"quyun/v2/pkg/consts"

 	"go.ipao.vip/gen"
@@ -18,25 +19,25 @@ const TableNameOrder = "orders"

 // Order mapped from table <orders>
 type Order struct {
-	ID                   int64              `gorm:"column:id;type:bigint;primaryKey;autoIncrement:true;comment:主键ID：自增；用于关联订单明细、账本流水、权益等" json:"id"`                                                              // 主键ID：自增；用于关联订单明细、账本流水、权益等
-	TenantID             int64              `gorm:"column:tenant_id;type:bigint;not null;comment:租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id" json:"tenant_id"`                                                          // 租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id
-	UserID               int64              `gorm:"column:user_id;type:bigint;not null;comment:用户ID：下单用户（buyer）；余额扣款与权益归属以该 user_id 为准" json:"user_id"`                                                           // 用户ID：下单用户（buyer）；余额扣款与权益归属以该 user_id 为准
-	Type                 consts.OrderType   `gorm:"column:type;type:character varying(32);not null;default:content_purchase;comment:订单类型：content_purchase（购买内容）/topup（充值）等；当前默认 content_purchase" json:"type"`    // 订单类型：content_purchase（购买内容）/topup（充值）等；当前默认 content_purchase
-	Status               consts.OrderStatus `gorm:"column:status;type:character varying(32);not null;default:created;comment:订单状态：created/paid/refunding/refunded/canceled/failed；状态变更需与账本/权益保持一致" json:"status"` // 订单状态：created/paid/refunding/refunded/canceled/failed；状态变更需与账本/权益保持一致
-	Currency             consts.Currency    `gorm:"column:currency;type:character varying(16);not null;default:CNY;comment:币种：当前固定 CNY；金额单位为分" json:"currency"`                                                   // 币种：当前固定 CNY；金额单位为分
-	AmountOriginal       int64              `gorm:"column:amount_original;type:bigint;not null;comment:原价金额：分；未折扣前金额（用于展示与对账）" json:"amount_original"`                                                            // 原价金额：分；未折扣前金额（用于展示与对账）
-	AmountDiscount       int64              `gorm:"column:amount_discount;type:bigint;not null;comment:优惠金额：分；amount_paid = amount_original - amount_discount（下单时快照）" json:"amount_discount"`                     // 优惠金额：分；amount_paid = amount_original - amount_discount（下单时快照）
-	AmountPaid           int64              `gorm:"column:amount_paid;type:bigint;not null;comment:实付金额：分；从租户内余额扣款的金额（下单时快照）" json:"amount_paid"`                                                                 // 实付金额：分；从租户内余额扣款的金额（下单时快照）
-	Snapshot             types.JSON         `gorm:"column:snapshot;type:jsonb;not null;default:{};comment:订单快照：JSON；建议包含 content 标题/定价/折扣、请求来源等，避免改价影响历史展示" json:"snapshot"`                                      // 订单快照：JSON；建议包含 content 标题/定价/折扣、请求来源等，避免改价影响历史展示
-	IdempotencyKey       string             `gorm:"column:idempotency_key;type:character varying(128);not null;comment:幂等键：同一租户同一用户同一业务请求可用；用于防重复下单/重复扣款（建议由客户端生成）" json:"idempotency_key"`                       // 幂等键：同一租户同一用户同一业务请求可用；用于防重复下单/重复扣款（建议由客户端生成）
-	PaidAt               time.Time          `gorm:"column:paid_at;type:timestamp with time zone;comment:支付/扣款完成时间：余额支付在 debit_purchase 成功后写入" json:"paid_at"`                                                     // 支付/扣款完成时间：余额支付在 debit_purchase 成功后写入
-	RefundedAt           time.Time          `gorm:"column:refunded_at;type:timestamp with time zone;comment:退款完成时间：退款落账成功后写入" json:"refunded_at"`                                                                 // 退款完成时间：退款落账成功后写入
-	RefundForced         bool               `gorm:"column:refund_forced;type:boolean;not null;comment:是否强制退款：true 表示租户管理侧绕过时间窗执行退款（需审计）" json:"refund_forced"`                                                    // 是否强制退款：true 表示租户管理侧绕过时间窗执行退款（需审计）
-	RefundOperatorUserID int64              `gorm:"column:refund_operator_user_id;type:bigint;comment:退款操作人用户ID：租户管理员/系统；用于审计与追责" json:"refund_operator_user_id"`                                                 // 退款操作人用户ID：租户管理员/系统；用于审计与追责
-	RefundReason         string             `gorm:"column:refund_reason;type:character varying(255);not null;comment:退款原因：后台/用户发起退款的原因说明；用于审计" json:"refund_reason"`                                              // 退款原因：后台/用户发起退款的原因说明；用于审计
-	CreatedAt            time.Time          `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()；用于审计与排序" json:"created_at"`                                       // 创建时间：默认 now()；用于审计与排序
-	UpdatedAt            time.Time          `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()；状态变更/退款写入时更新" json:"updated_at"`                                  // 更新时间：默认 now()；状态变更/退款写入时更新
-	Items                []*OrderItem       `gorm:"foreignKey:OrderID;references:ID" json:"items,omitempty"`
+	ID                   int64                                 `gorm:"column:id;type:bigint;primaryKey;autoIncrement:true;comment:主键ID：自增；用于关联订单明细、账本流水、权益等" json:"id"`                                                              // 主键ID：自增；用于关联订单明细、账本流水、权益等
+	TenantID             int64                                 `gorm:"column:tenant_id;type:bigint;not null;comment:租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id" json:"tenant_id"`                                                          // 租户ID：多租户隔离关键字段；所有查询/写入必须限定 tenant_id
+	UserID               int64                                 `gorm:"column:user_id;type:bigint;not null;comment:用户ID：下单用户（buyer）；余额扣款与权益归属以该 user_id 为准" json:"user_id"`                                                           // 用户ID：下单用户（buyer）；余额扣款与权益归属以该 user_id 为准
+	Type                 consts.OrderType                      `gorm:"column:type;type:character varying(32);not null;default:content_purchase;comment:订单类型：content_purchase（购买内容）/topup（充值）等；当前默认 content_purchase" json:"type"`    // 订单类型：content_purchase（购买内容）/topup（充值）等；当前默认 content_purchase
+	Status               consts.OrderStatus                    `gorm:"column:status;type:character varying(32);not null;default:created;comment:订单状态：created/paid/refunding/refunded/canceled/failed；状态变更需与账本/权益保持一致" json:"status"` // 订单状态：created/paid/refunding/refunded/canceled/failed；状态变更需与账本/权益保持一致
+	Currency             consts.Currency                       `gorm:"column:currency;type:character varying(16);not null;default:CNY;comment:币种：当前固定 CNY；金额单位为分" json:"currency"`                                                   // 币种：当前固定 CNY；金额单位为分
+	AmountOriginal       int64                                 `gorm:"column:amount_original;type:bigint;not null;comment:原价金额：分；未折扣前金额（用于展示与对账）" json:"amount_original"`                                                            // 原价金额：分；未折扣前金额（用于展示与对账）
+	AmountDiscount       int64                                 `gorm:"column:amount_discount;type:bigint;not null;comment:优惠金额：分；amount_paid = amount_original - amount_discount（下单时快照）" json:"amount_discount"`                     // 优惠金额：分；amount_paid = amount_original - amount_discount（下单时快照）
+	AmountPaid           int64                                 `gorm:"column:amount_paid;type:bigint;not null;comment:实付金额：分；从租户内余额扣款的金额（下单时快照）" json:"amount_paid"`                                                                 // 实付金额：分；从租户内余额扣款的金额（下单时快照）
+	Snapshot             types.JSONType[fields.OrdersSnapshot] `gorm:"column:snapshot;type:jsonb;not null;default:{};comment:订单快照：JSON；建议包含 content 标题/定价/折扣、请求来源等，避免改价影响历史展示" json:"snapshot"`                                      // 订单快照：JSON；建议包含 content 标题/定价/折扣、请求来源等，避免改价影响历史展示
+	IdempotencyKey       string                                `gorm:"column:idempotency_key;type:character varying(128);not null;comment:幂等键：同一租户同一用户同一业务请求可用；用于防重复下单/重复扣款（建议由客户端生成）" json:"idempotency_key"`                       // 幂等键：同一租户同一用户同一业务请求可用；用于防重复下单/重复扣款（建议由客户端生成）
+	PaidAt               time.Time                             `gorm:"column:paid_at;type:timestamp with time zone;comment:支付/扣款完成时间：余额支付在 debit_purchase 成功后写入" json:"paid_at"`                                                     // 支付/扣款完成时间：余额支付在 debit_purchase 成功后写入
+	RefundedAt           time.Time                             `gorm:"column:refunded_at;type:timestamp with time zone;comment:退款完成时间：退款落账成功后写入" json:"refunded_at"`                                                                 // 退款完成时间：退款落账成功后写入
+	RefundForced         bool                                  `gorm:"column:refund_forced;type:boolean;not null;comment:是否强制退款：true 表示租户管理侧绕过时间窗执行退款（需审计）" json:"refund_forced"`                                                    // 是否强制退款：true 表示租户管理侧绕过时间窗执行退款（需审计）
+	RefundOperatorUserID int64                                 `gorm:"column:refund_operator_user_id;type:bigint;comment:退款操作人用户ID：租户管理员/系统；用于审计与追责" json:"refund_operator_user_id"`                                                 // 退款操作人用户ID：租户管理员/系统；用于审计与追责
+	RefundReason         string                                `gorm:"column:refund_reason;type:character varying(255);not null;comment:退款原因：后台/用户发起退款的原因说明；用于审计" json:"refund_reason"`                                              // 退款原因：后台/用户发起退款的原因说明；用于审计
+	CreatedAt            time.Time                             `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()；用于审计与排序" json:"created_at"`                                       // 创建时间：默认 now()；用于审计与排序
+	UpdatedAt            time.Time                             `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()；状态变更/退款写入时更新" json:"updated_at"`                                  // 更新时间：默认 now()；状态变更/退款写入时更新
+	Items                []*OrderItem                          `gorm:"foreignKey:OrderID;references:ID" json:"items,omitempty"`
 }

 // Quick operations without importing query package
--- a/backend/docs/docs.go
+++ b/backend/docs/docs.go
@@ -2793,6 +2793,17 @@ const docTemplate = `{
                "MediaAssetTypeImage"
            ]
        },
+        "consts.MediaAssetVariant": {
+            "type": "string",
+            "enum": [
+                "main",
+                "preview"
+            ],
+            "x-enum-varnames": [
+                "MediaAssetVariantMain",
+                "MediaAssetVariantPreview"
+            ]
+        },
        "consts.OrderStatus": {
            "type": "string",
            "enum": [
@@ -3056,7 +3067,11 @@ const docTemplate = `{
                },
                "variant": {
                    "description": "Variant indicates whether this asset is a main or preview product.\nAllowed: main/preview; default is main.",
-                    "type": "string"
+                    "allOf": [
+                        {
+                            "$ref": "#/definitions/consts.MediaAssetVariant"
+                        }
+                    ]
                }
            }
        },
@@ -4061,6 +4076,10 @@ const docTemplate = `{
                    "description": "存储提供方：例如 s3/minio/oss；便于多存储扩展",
                    "type": "string"
                },
+                "source_asset_id": {
+                    "description": "派生来源资源ID：preview 产物可指向对应 main 资源；用于建立 preview/main 的 1:1 追溯关系",
+                    "type": "integer"
+                },
                "status": {
                    "description": "处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供",
                    "allOf": [
@@ -4088,6 +4107,14 @@ const docTemplate = `{
                "user_id": {
                    "description": "用户ID：资源上传者；用于审计与权限控制",
                    "type": "integer"
+                },
+                "variant": {
+                    "description": "产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过",
+                    "allOf": [
+                        {
+                            "$ref": "#/definitions/consts.MediaAssetVariant"
+                        }
+                    ]
                }
            }
        },
--- a/backend/docs/swagger.json
+++ b/backend/docs/swagger.json
@@ -2787,6 +2787,17 @@
                "MediaAssetTypeImage"
            ]
        },
+        "consts.MediaAssetVariant": {
+            "type": "string",
+            "enum": [
+                "main",
+                "preview"
+            ],
+            "x-enum-varnames": [
+                "MediaAssetVariantMain",
+                "MediaAssetVariantPreview"
+            ]
+        },
        "consts.OrderStatus": {
            "type": "string",
            "enum": [
@@ -3050,7 +3061,11 @@
                },
                "variant": {
                    "description": "Variant indicates whether this asset is a main or preview product.\nAllowed: main/preview; default is main.",
-                    "type": "string"
+                    "allOf": [
+                        {
+                            "$ref": "#/definitions/consts.MediaAssetVariant"
+                        }
+                    ]
                }
            }
        },
@@ -4055,6 +4070,10 @@
                    "description": "存储提供方：例如 s3/minio/oss；便于多存储扩展",
                    "type": "string"
                },
+                "source_asset_id": {
+                    "description": "派生来源资源ID：preview 产物可指向对应 main 资源；用于建立 preview/main 的 1:1 追溯关系",
+                    "type": "integer"
+                },
                "status": {
                    "description": "处理状态：uploaded/processing/ready/failed/deleted；ready 才可被内容引用对外提供",
                    "allOf": [
@@ -4082,6 +4101,14 @@
                "user_id": {
                    "description": "用户ID：资源上传者；用于审计与权限控制",
                    "type": "integer"
+                },
+                "variant": {
+                    "description": "产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过",
+                    "allOf": [
+                        {
+                            "$ref": "#/definitions/consts.MediaAssetVariant"
+                        }
+                    ]
                }
            }
        },
--- a/backend/docs/swagger.yaml
+++ b/backend/docs/swagger.yaml
@@ -84,6 +84,14 @@ definitions:
    - MediaAssetTypeVideo
    - MediaAssetTypeAudio
    - MediaAssetTypeImage
+  consts.MediaAssetVariant:
+    enum:
+    - main
+    - preview
+    type: string
+    x-enum-varnames:
+    - MediaAssetVariantMain
+    - MediaAssetVariantPreview
  consts.OrderStatus:
    enum:
    - created
@@ -299,10 +307,11 @@ definitions:
          Used to decide processing pipeline and validation rules; required.
        type: string
      variant:
+        allOf:
+        - $ref: '#/definitions/consts.MediaAssetVariant'
        description: |-
          Variant indicates whether this asset is a main or preview product.
          Allowed: main/preview; default is main.
-        type: string
    type: object
  dto.AdminMediaAssetUploadInitResponse:
    properties:
@@ -976,6 +985,9 @@ definitions:
      provider:
        description: 存储提供方：例如 s3/minio/oss；便于多存储扩展
        type: string
+      source_asset_id:
+        description: 派生来源资源ID：preview 产物可指向对应 main 资源；用于建立 preview/main 的 1:1 追溯关系
+        type: integer
      status:
        allOf:
        - $ref: '#/definitions/consts.MediaAssetStatus'
@@ -993,6 +1005,10 @@ definitions:
      user_id:
        description: 用户ID：资源上传者；用于审计与权限控制
        type: integer
+      variant:
+        allOf:
+        - $ref: '#/definitions/consts.MediaAssetVariant'
+        description: 产物类型：main/preview；用于强制试看资源必须绑定独立产物，避免用正片绕过
    type: object
  models.Order:
    properties:
--- a/backend/llm.txt
+++ b/backend/llm.txt
@@ -10,6 +10,7 @@ This file condenses `backend/docs/dev/http_api.md` + `backend/docs/dev/model.md`
 - MUST: HTTP module folder name MUST be `snake_case` (e.g. `tenant_public`), not `camelCase`/`mixedCase`.
 - DO keep controller methods thin: parse/bind → call `services.*` → return result/error.
 - DO regenerate code after changes (routes/docs/models).
+- MUST: in `backend/app/services`, prefer the generated GORM-Gen DAO (`backend/database/models/*`) for DB access; treat raw `*gorm.DB` usage as a last resort.
 - MUST: after adding/removing/renaming any files under `backend/app/services/`, run `atomctl gen service --path ./app/services` to regenerate `backend/app/services/services.gen.go`; DO NOT edit `services.gen.go` manually.
 - MUST: a single service's methods MUST live in a single file; do NOT split one service across multiple files (e.g. `type user struct{}` in `user.go` but methods in `user_admin.go`), because `atomctl gen service` uses filenames to infer services and will generate incorrect `services.gen.go`.
 - DO add `// @provider` above every controller/service `struct` declaration.
@@ -155,6 +156,42 @@ Models live in:

 - `atomctl gen model`

+---
+
+## 3) Service-layer DB access (GORM Gen)
+
+This project uses a PostgreSQL-focused GORM-Gen variant (`go.ipao.vip/gen` + generated `backend/database/models/*`).
+Reference: `backend/llm.gorm_gen.txt`.
+
+### 3.1 Query style (preferred)
+
+- MUST: in services, build queries via:
+  - `tbl, q := models.<Table>Query.QueryContext(ctx)`
+  - Use type-safe conditions (`tbl.ID.Eq(...)`, `tbl.TenantID.Eq(...)`, `tbl.DeletedAt.IsNull()`, etc).
+- DO NOT: use string SQL in `Where("...")` unless absolutely necessary.
+
+### 3.2 Transactions
+
+- MUST: use Gen transaction wrapper so all queries share the same tx connection:
+  - `models.Q.Transaction(func(tx *models.Query) error { ... })`
+  - Inside tx, use `tx.<Table>.QueryContext(ctx)` / `tx.<Table>.WithContext(ctx)`
+- DO NOT: use `_db.WithContext(ctx).Transaction(...)` in services unless Gen cannot express a required operation.
+
+### 3.3 Updates
+
+- Prefer `UpdateSimple(...)` with typed assign expressions when possible.
+- Otherwise use `Updates(map[string]any{...})`, but MUST:
+  - include tenant boundary conditions (`tenant_id`) in the WHERE,
+  - avoid updating columns by concatenating user input.
+
+### 3.4 Columns not in generated models (temporary escape hatch)
+
+If migrations add columns but `atomctl gen model` has not been re-run yet, the typed `models.<Struct>` will not contain those fields.
+In this case:
+- Use `q.UnderlyingDB()` (from Gen DO) to do a narrow query/update (single table, explicit columns).
+- Add a short Chinese comment explaining why, and that `atomctl gen model` should be run when DB is reachable.
+- Avoid spreading this pattern: keep it localized to one function.
+
 ### 2.2 Enum strategy

 - DO NOT use native DB ENUM.
@@ -181,6 +218,26 @@ type UserStatus string
 Common types:

 - JSON: `types.JSON`, `types.JSONMap`, `types.JSONType[T]`, `types.JSONSlice[T]`
+
+### 2.4 JSONB 强类型规则（`types.JSONType[T]`）
+
+- 如果某个 `jsonb` 字段的数据结构是“确定且稳定”的，优先将 `types.JSON` 升级为 `types.JSONType[fields.TableNameFieldName]`，以获得类型约束与更清晰的读写代码。
+- `fields.TableNameFieldName` 必须定义在 `backend/database/fields/[table_name].go` 中，格式为 `type TableNameFieldName struct { ... }` 并为每个字段写好 `json` tag。
+- 如果数据结构“不确定/随业务演进/允许任意键”，继续使用 `types.JSON`（不要强行 JSONType，以免丢字段或引入频繁迁移）。
+- 服务层读写 `types.JSONType[T]`：
+  - 读取：`v := model.Field.Data()`
+  - 修改：`model.Field.Edit(func(v *T) { ... })` 或 `model.Field.Set(newValue)`
+
+### 2.5 一个字段多种结构（判别联合）
+
+- 当同一个 `jsonb` 字段存在多种不同结构（例如订单快照：充值 vs 购买），不要让字段类型漂移为 `any/map`。
+- 推荐统一包裹为“判别联合”结构：`type Xxx struct { Kind string; Data json.RawMessage }`，并将该字段映射为 `types.JSONType[fields.Xxx]`。
+- 写入时：
+  - `Kind` 建议与业务枚举对齐（例如订单类型），便于 SQL/报表按 `kind` 过滤。
+  - `Data` 写入对应 payload 的 JSON（payload 可以是多个不同 struct）。
+- 读取时：
+  - 先 `snap := model.Snapshot.Data()`，再 `switch snap.Kind` 选择对应 payload 结构去 `json.Unmarshal(snap.Data, &payload)`。
+- 兼容历史数据（旧 JSON 没有 kind/data）时，`UnmarshalJSON` 可以将其标记为 `legacy` 并把原始 JSON 放入 `Data`，避免线上存量读取失败。
 - Array: `types.Array[T]`
 - UUID: `types.UUID`, `types.BinUUID`
 - Date/Time: `types.Date`, `types.Time`
--- a/backend/pkg/consts/consts.gen.go
+++ b/backend/pkg/consts/consts.gen.go
@@ -1343,6 +1343,166 @@ func (x NullMediaAssetTypeStr) Value() (driver.Value, error) {
 	return x.MediaAssetType.String(), nil
 }

+const (
+	// MediaAssetVariantMain is a MediaAssetVariant of type main.
+	MediaAssetVariantMain MediaAssetVariant = "main"
+	// MediaAssetVariantPreview is a MediaAssetVariant of type preview.
+	MediaAssetVariantPreview MediaAssetVariant = "preview"
+)
+
+var ErrInvalidMediaAssetVariant = fmt.Errorf("not a valid MediaAssetVariant, try [%s]", strings.Join(_MediaAssetVariantNames, ", "))
+
+var _MediaAssetVariantNames = []string{
+	string(MediaAssetVariantMain),
+	string(MediaAssetVariantPreview),
+}
+
+// MediaAssetVariantNames returns a list of possible string values of MediaAssetVariant.
+func MediaAssetVariantNames() []string {
+	tmp := make([]string, len(_MediaAssetVariantNames))
+	copy(tmp, _MediaAssetVariantNames)
+	return tmp
+}
+
+// MediaAssetVariantValues returns a list of the values for MediaAssetVariant
+func MediaAssetVariantValues() []MediaAssetVariant {
+	return []MediaAssetVariant{
+		MediaAssetVariantMain,
+		MediaAssetVariantPreview,
+	}
+}
+
+// String implements the Stringer interface.
+func (x MediaAssetVariant) String() string {
+	return string(x)
+}
+
+// IsValid provides a quick way to determine if the typed value is
+// part of the allowed enumerated values
+func (x MediaAssetVariant) IsValid() bool {
+	_, err := ParseMediaAssetVariant(string(x))
+	return err == nil
+}
+
+var _MediaAssetVariantValue = map[string]MediaAssetVariant{
+	"main":    MediaAssetVariantMain,
+	"preview": MediaAssetVariantPreview,
+}
+
+// ParseMediaAssetVariant attempts to convert a string to a MediaAssetVariant.
+func ParseMediaAssetVariant(name string) (MediaAssetVariant, error) {
+	if x, ok := _MediaAssetVariantValue[name]; ok {
+		return x, nil
+	}
+	return MediaAssetVariant(""), fmt.Errorf("%s is %w", name, ErrInvalidMediaAssetVariant)
+}
+
+var errMediaAssetVariantNilPtr = errors.New("value pointer is nil") // one per type for package clashes
+
+// Scan implements the Scanner interface.
+func (x *MediaAssetVariant) Scan(value interface{}) (err error) {
+	if value == nil {
+		*x = MediaAssetVariant("")
+		return
+	}
+
+	// A wider range of scannable types.
+	// driver.Value values at the top of the list for expediency
+	switch v := value.(type) {
+	case string:
+		*x, err = ParseMediaAssetVariant(v)
+	case []byte:
+		*x, err = ParseMediaAssetVariant(string(v))
+	case MediaAssetVariant:
+		*x = v
+	case *MediaAssetVariant:
+		if v == nil {
+			return errMediaAssetVariantNilPtr
+		}
+		*x = *v
+	case *string:
+		if v == nil {
+			return errMediaAssetVariantNilPtr
+		}
+		*x, err = ParseMediaAssetVariant(*v)
+	default:
+		return errors.New("invalid type for MediaAssetVariant")
+	}
+
+	return
+}
+
+// Value implements the driver Valuer interface.
+func (x MediaAssetVariant) Value() (driver.Value, error) {
+	return x.String(), nil
+}
+
+// Set implements the Golang flag.Value interface func.
+func (x *MediaAssetVariant) Set(val string) error {
+	v, err := ParseMediaAssetVariant(val)
+	*x = v
+	return err
+}
+
+// Get implements the Golang flag.Getter interface func.
+func (x *MediaAssetVariant) Get() interface{} {
+	return *x
+}
+
+// Type implements the github.com/spf13/pFlag Value interface.
+func (x *MediaAssetVariant) Type() string {
+	return "MediaAssetVariant"
+}
+
+type NullMediaAssetVariant struct {
+	MediaAssetVariant MediaAssetVariant
+	Valid             bool
+}
+
+func NewNullMediaAssetVariant(val interface{}) (x NullMediaAssetVariant) {
+	err := x.Scan(val) // yes, we ignore this error, it will just be an invalid value.
+	_ = err            // make any errcheck linters happy
+	return
+}
+
+// Scan implements the Scanner interface.
+func (x *NullMediaAssetVariant) Scan(value interface{}) (err error) {
+	if value == nil {
+		x.MediaAssetVariant, x.Valid = MediaAssetVariant(""), false
+		return
+	}
+
+	err = x.MediaAssetVariant.Scan(value)
+	x.Valid = (err == nil)
+	return
+}
+
+// Value implements the driver Valuer interface.
+func (x NullMediaAssetVariant) Value() (driver.Value, error) {
+	if !x.Valid {
+		return nil, nil
+	}
+	// driver.Value accepts int64 for int values.
+	return string(x.MediaAssetVariant), nil
+}
+
+type NullMediaAssetVariantStr struct {
+	NullMediaAssetVariant
+}
+
+func NewNullMediaAssetVariantStr(val interface{}) (x NullMediaAssetVariantStr) {
+	x.Scan(val) // yes, we ignore this error, it will just be an invalid value.
+	return
+}
+
+// Value implements the driver Valuer interface.
+func (x NullMediaAssetVariantStr) Value() (driver.Value, error) {
+	if !x.Valid {
+		return nil, nil
+	}
+	return x.MediaAssetVariant.String(), nil
+}
+
 const (
 	// OrderStatusCreated is a OrderStatus of type created.
 	OrderStatusCreated OrderStatus = "created"
--- a/backend/pkg/consts/consts.go
+++ b/backend/pkg/consts/consts.go
@@ -185,6 +185,32 @@ func MediaAssetStatusItems() []requests.KV {
 	return items
 }

+// swagger:enum MediaAssetVariant
+// ENUM( main, preview )
+type MediaAssetVariant string
+
+// Description returns the Chinese label for the specific enum value.
+func (t MediaAssetVariant) Description() string {
+	switch t {
+	case MediaAssetVariantMain:
+		return "正片产物"
+	case MediaAssetVariantPreview:
+		return "试看产物"
+	default:
+		return "未知产物"
+	}
+}
+
+// MediaAssetVariantItems returns the KV list for FE dropdowns.
+func MediaAssetVariantItems() []requests.KV {
+	values := MediaAssetVariantValues()
+	items := make([]requests.KV, 0, len(values))
+	for _, v := range values {
+		items = append(items, requests.NewKV(string(v), v.Description()))
+	}
+	return items
+}
+
 // contents

 // swagger:enum ContentStatus
Author	SHA1	Message	Date
Rogee	683965ae39	feat: Refactor order snapshot handling and introduce structured snapshot types - Added new structured snapshot types for orders and order items to improve data integrity and clarity. - Updated the Order and OrderItem models to use the new JSONType for snapshots. - Refactored tests to accommodate the new snapshot structure, ensuring compatibility with legacy data. - Enhanced the OrdersSnapshot struct to support multiple snapshot types and maintain backward compatibility. - Introduced new fields for order items and orders to capture detailed snapshot information for auditing and historical display.	2025-12-22 21:11:33 +08:00
Rogee	618fe116ba	update llm.txt	2025-12-22 21:11:13 +08:00
Rogee	83097c8ff4	update llm.txt	2025-12-22 20:59:24 +08:00
Rogee	2cc823d3a8	feat: Introduce MediaAssetVariant for better asset management - Added MediaAssetVariant enum with values 'main' and 'preview'. - Updated media asset service logic to utilize MediaAssetVariant for variant handling. - Refactored database models and queries to include variant and source_asset_id fields. - Enhanced validation for asset variants in upload and processing functions. - Updated Swagger documentation to reflect new variant structure and descriptions. - Implemented necessary database migrations to support the new variant constraints.	2025-12-22 19:27:31 +08:00
Rogee	d04e2ee693	update llm.txt	2025-12-22 18:56:44 +08:00