refactor: 将 DTO 文件从 internal/model 移动到 internal/model/dto 目录

- 移动 17 个 DTO 文件到 internal/model/dto/ 目录
- 更新所有 DTO 文件的 package 声明从 model 改为 dto
- 更新所有引用文件的 import 和类型引用
  - Handler 层：admin 和 h5 所有处理器
  - Service 层：所有业务服务
  - Routes 层：所有路由定义
  - Tests 层：单元测试和集成测试
- 清理未使用的 import 语句
- 验证：项目构建成功，测试编译通过，LSP 无错误

internal/service/customer_account/service.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/break/junhong_cmp_fiber/internal/model"
+	"github.com/break/junhong_cmp_fiber/internal/model/dto"
 	"github.com/break/junhong_cmp_fiber/internal/store/postgres"
 	"github.com/break/junhong_cmp_fiber/pkg/constants"
 	"github.com/break/junhong_cmp_fiber/pkg/errors"
@@ -34,7 +35,7 @@ func New(
 	}
 }
 
-func (s *Service) List(ctx context.Context, req *model.CustomerAccountListReq) (*model.CustomerAccountPageResult, error) {
+func (s *Service) List(ctx context.Context, req *dto.CustomerAccountListReq) (*dto.CustomerAccountPageResult, error) {
 	page := req.Page
 	pageSize := req.PageSize
 	if page == 0 {
@@ -106,7 +107,7 @@ func (s *Service) List(ctx context.Context, req *model.CustomerAccountListReq) (
 		}
 	}
 
-	items := make([]model.CustomerAccountItem, 0, len(accounts))
+	items := make([]dto.CustomerAccountItem, 0, len(accounts))
 	for _, acc := range accounts {
 		shopName := ""
 		if acc.ShopID != nil {
@@ -116,7 +117,7 @@ func (s *Service) List(ctx context.Context, req *model.CustomerAccountListReq) (
 		if acc.EnterpriseID != nil {
 			enterpriseName = enterpriseMap[*acc.EnterpriseID]
 		}
-		items = append(items, model.CustomerAccountItem{
+		items = append(items, dto.CustomerAccountItem{
 			ID:             acc.ID,
 			Username:       acc.Username,
 			Phone:          acc.Phone,
@@ -132,7 +133,7 @@ func (s *Service) List(ctx context.Context, req *model.CustomerAccountListReq) (
 		})
 	}
 
-	return &model.CustomerAccountPageResult{
+	return &dto.CustomerAccountPageResult{
 		Items: items,
 		Total: total,
 		Page:  page,
@@ -140,7 +141,7 @@ func (s *Service) List(ctx context.Context, req *model.CustomerAccountListReq) (
 	}, nil
 }
 
-func (s *Service) Create(ctx context.Context, req *model.CreateCustomerAccountReq) (*model.CustomerAccountItem, error) {
+func (s *Service) Create(ctx context.Context, req *dto.CreateCustomerAccountReq) (*dto.CustomerAccountItem, error) {
 	currentUserID := middleware.GetUserIDFromContext(ctx)
 	if currentUserID == 0 {
 		return nil, errors.New(errors.CodeUnauthorized, "未授权访问")
@@ -182,7 +183,7 @@ func (s *Service) Create(ctx context.Context, req *model.CreateCustomerAccountRe
 		shopName = shop.ShopName
 	}
 
-	return &model.CustomerAccountItem{
+	return &dto.CustomerAccountItem{
 		ID:           account.ID,
 		Username:     account.Username,
 		Phone:        account.Phone,
@@ -196,7 +197,7 @@ func (s *Service) Create(ctx context.Context, req *model.CreateCustomerAccountRe
 	}, nil
 }
 
-func (s *Service) Update(ctx context.Context, id uint, req *model.UpdateCustomerAccountRequest) (*model.CustomerAccountItem, error) {
+func (s *Service) Update(ctx context.Context, id uint, req *dto.UpdateCustomerAccountRequest) (*dto.CustomerAccountItem, error) {
 	currentUserID := middleware.GetUserIDFromContext(ctx)
 	if currentUserID == 0 {
 		return nil, errors.New(errors.CodeUnauthorized, "未授权访问")
@@ -242,7 +243,7 @@ func (s *Service) Update(ctx context.Context, id uint, req *model.UpdateCustomer
 		}
 	}
 
-	return &model.CustomerAccountItem{
+	return &dto.CustomerAccountItem{
 		ID:             account.ID,
 		Username:       account.Username,
 		Phone:          account.Phone,