feat: 实现客户端换货系统（client-exchange-system）

新增完整换货生命周期管理：后台发起 → 客户端填收货信息 → 后台发货 → 确认完成（含可选全量迁移） → 旧资产转新再销售

后台接口（7个）：
- POST /api/admin/exchanges（发起换货）
- GET /api/admin/exchanges（换货列表）
- GET /api/admin/exchanges/:id（换货详情）
- POST /api/admin/exchanges/:id/ship（发货）
- POST /api/admin/exchanges/:id/complete（确认完成+可选迁移）
- POST /api/admin/exchanges/:id/cancel（取消）
- POST /api/admin/exchanges/:id/renew（旧资产转新）

客户端接口（2个）：
- GET /api/c/v1/exchange/pending（查询换货通知）
- POST /api/c/v1/exchange/:id/shipping-info（填写收货信息）

核心能力：
- ExchangeOrder 模型与状态机（1待填写→2待发货→3已发货→4已完成，1/2可取消→5）
- 全量迁移事务（11张表：钱包、套餐、标签、客户绑定等）
- 旧资产转新（generation+1、状态重置、新钱包、历史隔离）
- 旧 CardReplacementRecord 表改名为 legacy，is_replaced 过滤改为查新表
- 数据库迁移：000085 新建 tb_exchange_order，000086 旧表改名

internal/store/postgres/exchange_order_store.go

@@ -0,0 +1,106 @@
+package postgres
+
+import (
+	"context"
+	"maps"
+	"time"
+
+	"github.com/break/junhong_cmp_fiber/internal/model"
+	"github.com/break/junhong_cmp_fiber/pkg/constants"
+	"github.com/break/junhong_cmp_fiber/pkg/middleware"
+	"gorm.io/gorm"
+)
+
+type ExchangeOrderStore struct {
+	db *gorm.DB
+}
+
+func NewExchangeOrderStore(db *gorm.DB) *ExchangeOrderStore {
+	return &ExchangeOrderStore{db: db}
+}
+
+func (s *ExchangeOrderStore) Create(ctx context.Context, order *model.ExchangeOrder) error {
+	return s.db.WithContext(ctx).Create(order).Error
+}
+
+func (s *ExchangeOrderStore) GetByID(ctx context.Context, id uint) (*model.ExchangeOrder, error) {
+	var order model.ExchangeOrder
+	query := s.db.WithContext(ctx).Where("id = ?", id)
+	query = middleware.ApplyShopFilter(ctx, query)
+	if err := query.First(&order).Error; err != nil {
+		return nil, err
+	}
+	return &order, nil
+}
+
+func (s *ExchangeOrderStore) List(ctx context.Context, filters map[string]any, page, pageSize int) ([]*model.ExchangeOrder, int64, error) {
+	var orders []*model.ExchangeOrder
+	var total int64
+
+	query := s.db.WithContext(ctx).Model(&model.ExchangeOrder{})
+	query = middleware.ApplyShopFilter(ctx, query)
+
+	if status, ok := filters["status"].(int); ok && status > 0 {
+		query = query.Where("status = ?", status)
+	}
+	if identifier, ok := filters["identifier"].(string); ok && identifier != "" {
+		like := "%" + identifier + "%"
+		query = query.Where("old_asset_identifier LIKE ? OR new_asset_identifier LIKE ?", like, like)
+	}
+	if createdAtStart, ok := filters["created_at_start"].(time.Time); ok && !createdAtStart.IsZero() {
+		query = query.Where("created_at >= ?", createdAtStart)
+	}
+	if createdAtEnd, ok := filters["created_at_end"].(time.Time); ok && !createdAtEnd.IsZero() {
+		query = query.Where("created_at <= ?", createdAtEnd)
+	}
+
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	if page < 1 {
+		page = 1
+	}
+	if pageSize < 1 {
+		pageSize = constants.DefaultPageSize
+	}
+	if pageSize > constants.MaxPageSize {
+		pageSize = constants.MaxPageSize
+	}
+
+	offset := (page - 1) * pageSize
+	if err := query.Order("created_at DESC").Offset(offset).Limit(pageSize).Find(&orders).Error; err != nil {
+		return nil, 0, err
+	}
+
+	return orders, total, nil
+}
+
+func (s *ExchangeOrderStore) UpdateStatus(ctx context.Context, id uint, fromStatus, toStatus int, updates map[string]any) error {
+	values := make(map[string]any, len(updates)+1)
+	maps.Copy(values, updates)
+	values["status"] = toStatus
+
+	result := s.db.WithContext(ctx).Model(&model.ExchangeOrder{}).
+		Where("id = ? AND status = ?", id, fromStatus).
+		Updates(values)
+	if result.Error != nil {
+		return result.Error
+	}
+	if result.RowsAffected == 0 {
+		return gorm.ErrRecordNotFound
+	}
+	return nil
+}
+
+func (s *ExchangeOrderStore) FindActiveByOldAsset(ctx context.Context, assetType string, assetID uint) (*model.ExchangeOrder, error) {
+	var order model.ExchangeOrder
+	query := s.db.WithContext(ctx).
+		Where("old_asset_type = ? AND old_asset_id = ?", assetType, assetID).
+		Where("status IN ?", []int{constants.ExchangeStatusPendingInfo, constants.ExchangeStatusPendingShip, constants.ExchangeStatusShipped})
+	query = middleware.ApplyShopFilter(ctx, query)
+	if err := query.Order("id DESC").First(&order).Error; err != nil {
+		return nil, err
+	}
+	return &order, nil
+}

internal/store/postgres/iot_card_store.go

@@ -644,14 +644,14 @@ func (s *IotCardStore) applyStandaloneFilters(ctx context.Context, query *gorm.D
 	if isReplaced, ok := filters["is_replaced"].(bool); ok {
 		if isReplaced {
 			query = query.Where("id IN (?)",
-				s.db.WithContext(ctx).Table("tb_card_replacement_record").
-					Select("old_iot_card_id").
-					Where("deleted_at IS NULL"))
+				s.db.WithContext(ctx).Table("tb_exchange_order").
+					Select("old_asset_id").
+					Where("old_asset_type = ? AND status IN ? AND deleted_at IS NULL", constants.ExchangeAssetTypeIotCard, []int{constants.ExchangeStatusShipped, constants.ExchangeStatusCompleted}))
 		} else {
 			query = query.Where("id NOT IN (?)",
-				s.db.WithContext(ctx).Table("tb_card_replacement_record").
-					Select("old_iot_card_id").
-					Where("deleted_at IS NULL"))
+				s.db.WithContext(ctx).Table("tb_exchange_order").
+					Select("old_asset_id").
+					Where("old_asset_type = ? AND status IN ? AND deleted_at IS NULL", constants.ExchangeAssetTypeIotCard, []int{constants.ExchangeStatusShipped, constants.ExchangeStatusCompleted}))
 		}
 	}
 	if seriesID, ok := filters["series_id"].(uint); ok && seriesID > 0 {
@@ -836,7 +836,7 @@ func (s *IotCardStore) ListBySeriesID(ctx context.Context, seriesID uint) ([]*mo
 func (s *IotCardStore) UpdateRechargeTrackingFields(ctx context.Context, cardID uint, accumulatedJSON, triggeredJSON string) error {
 	return s.db.WithContext(ctx).Model(&model.IotCard{}).
 		Where("id = ?", cardID).
-		Updates(map[string]interface{}{
+		Updates(map[string]any{
 			"accumulated_recharge_by_series":     accumulatedJSON,
 			"first_recharge_triggered_by_series": triggeredJSON,
 		}).Error
@@ -961,8 +961,8 @@ func hashFilters(filters map[string]any) string {
 
 	h := fnv.New32a()
 	for _, k := range keys {
-		h.Write([]byte(k))
-		h.Write([]byte(fmt.Sprint(filters[k])))
+		_, _ = h.Write([]byte(k))
+		_, _ = fmt.Fprint(h, filters[k])
 	}
 	return fmt.Sprintf("%08x", h.Sum32())
 }

internal/store/postgres/resource_tag_store.go

@@ -0,0 +1,30 @@
+package postgres
+
+import (
+	"context"
+
+	"github.com/break/junhong_cmp_fiber/internal/model"
+	"gorm.io/gorm"
+)
+
+type ResourceTagStore struct {
+	db *gorm.DB
+}
+
+func NewResourceTagStore(db *gorm.DB) *ResourceTagStore {
+	return &ResourceTagStore{db: db}
+}
+
+func (s *ResourceTagStore) ListByResource(ctx context.Context, resourceType string, resourceID uint) ([]*model.ResourceTag, error) {
+	var list []*model.ResourceTag
+	if err := s.db.WithContext(ctx).
+		Where("resource_type = ? AND resource_id = ?", resourceType, resourceID).
+		Find(&list).Error; err != nil {
+		return nil, err
+	}
+	return list, nil
+}
+
+func (s *ResourceTagStore) Create(ctx context.Context, item *model.ResourceTag) error {
+	return s.db.WithContext(ctx).Create(item).Error
+}