功能：恢复商户账号分组查看

backend/internal/handler/user.go

@@ -29,6 +29,17 @@ func (h *UserHandler) ListPlatformAdmins(c *gin.Context) {
 	response.Page(c, list, total, page, size)
 }
 
+func (h *UserHandler) ListMerchantAccountGroups(c *gin.Context) {
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "20"))
+	list, total, err := h.svc.ListMerchantAccountGroups(page, size)
+	if err != nil {
+		response.ServerError(c, err.Error())
+		return
+	}
+	response.Page(c, list, total, page, size)
+}
+
 type createPlatformAdminReq struct {
 	Username string `json:"username" binding:"required"`
 	Password string `json:"password" binding:"required,min=6"`

backend/internal/router/router.go

@@ -193,6 +193,7 @@ func Setup(h *Handlers) *gin.Engine {
 			admin.Use(middleware.RequireRole(model.RoleAdmin))
 			{
 				admin.GET("/platform/admins", h.User.ListPlatformAdmins)
+				admin.GET("/platform/merchant-accounts", h.User.ListMerchantAccountGroups)
 				admin.POST("/platform/admins", h.User.CreatePlatformAdmin)
 				admin.PATCH("/platform/admins/:id", h.User.UpdatePlatformAdmin)
 				admin.DELETE("/platform/admins/:id", h.User.DeletePlatformAdmin)

backend/internal/service/merchant_test.go

@@ -266,6 +266,40 @@ func TestPlatformAdminCRUDDoesNotCreateMerchantMembership(t *testing.T) {
 	}
 }
 
+func TestListMerchantAccountGroupsExcludesPlatformAdmins(t *testing.T) {
+	db := newServiceTestDB(t)
+	merchantA := model.Merchant{Code: "merchant-accounts-a", Name: "商户账号 A", Status: model.MerchantStatusActive}
+	merchantB := model.Merchant{Code: "merchant-accounts-b", Name: "商户账号 B", Status: model.MerchantStatusActive}
+	employeeA := model.User{Username: "merchant-account-a", PasswordHash: "hash", Role: model.RoleMerchant, Status: 1}
+	employeeB := model.User{Username: "merchant-account-b", PasswordHash: "hash", Role: model.RoleMerchant, Status: 1}
+	admin := model.User{Username: "merchant-account-admin", PasswordHash: "hash", Role: model.RoleAdmin, Status: 1}
+	for _, entity := range []interface{}{&merchantA, &merchantB, &employeeA, &employeeB, &admin} {
+		if err := db.Create(entity).Error; err != nil {
+			t.Fatalf("create fixture: %v", err)
+		}
+	}
+	for _, member := range []model.MerchantMember{
+		{MerchantID: merchantA.ID, UserID: employeeA.ID, Role: model.MemberRoleOperator, Status: 1},
+		{MerchantID: merchantA.ID, UserID: employeeB.ID, Role: "support", Status: 1},
+		{MerchantID: merchantB.ID, UserID: admin.ID, Role: model.MemberRoleOwner, Status: 1},
+	} {
+		if err := db.Create(&member).Error; err != nil {
+			t.Fatalf("create membership: %v", err)
+		}
+	}
+
+	groups, total, err := NewUserService(db, nil).ListMerchantAccountGroups(1, 20)
+	if err != nil {
+		t.Fatalf("list merchant account groups: %v", err)
+	}
+	if total != 1 || len(groups) != 1 {
+		t.Fatalf("expected one merchant group, total=%d groups=%+v", total, groups)
+	}
+	if groups[0].MerchantID != merchantA.ID || groups[0].Merchant == nil || len(groups[0].Members) != 2 {
+		t.Fatalf("unexpected merchant account group: %+v", groups[0])
+	}
+}
+
 func TestEnsureAdminUsesConfiguredCredentialsOnlyForEmptyDatabase(t *testing.T) {
 	db := newServiceTestDB(t)
 	tenant := NewTenantService(db)

backend/internal/service/user.go

@@ -27,6 +27,14 @@ type UserListQuery struct {
 	Status     *int
 }
 
+// MerchantMemberGroup presents merchant accounts in their actual ownership
+// hierarchy: one merchant and all of its employee accounts.
+type MerchantMemberGroup struct {
+	MerchantID uint                   `json:"merchant_id"`
+	Merchant   *model.Merchant        `json:"merchant,omitempty"`
+	Members    []model.MerchantMember `json:"members"`
+}
+
 func (s *UserService) List(q UserListQuery) ([]model.User, int64, error) {
 	if q.Page < 1 {
 		q.Page = 1
@@ -123,6 +131,55 @@ func (s *UserService) ListPlatformAdmins(page, size int) ([]model.User, int64, e
 	return s.List(UserListQuery{Page: page, Size: size, Role: model.RoleAdmin})
 }
 
+// ListMerchantAccountGroups returns merchant employee accounts grouped by
+// merchant. Platform administrators are excluded from this independent view.
+func (s *UserService) ListMerchantAccountGroups(page, size int) ([]MerchantMemberGroup, int64, error) {
+	page, size = normalizePage(page, size)
+	tx := s.db.Model(&model.MerchantMember{}).
+		Joins("JOIN users ON users.id = merchant_members.user_id AND users.deleted_at IS NULL").
+		Where("users.role = ?", model.RoleMerchant)
+
+	var total int64
+	if err := tx.Distinct("merchant_members.merchant_id").Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	var merchantIDs []uint
+	if err := tx.Distinct("merchant_members.merchant_id").
+		Order("merchant_members.merchant_id ASC").
+		Offset((page-1)*size).Limit(size).
+		Pluck("merchant_members.merchant_id", &merchantIDs).Error; err != nil {
+		return nil, 0, err
+	}
+	if len(merchantIDs) == 0 {
+		return []MerchantMemberGroup{}, total, nil
+	}
+
+	var members []model.MerchantMember
+	if err := s.db.Model(&model.MerchantMember{}).
+		Joins("JOIN users ON users.id = merchant_members.user_id AND users.deleted_at IS NULL").
+		Where("users.role = ? AND merchant_members.merchant_id IN ?", model.RoleMerchant, merchantIDs).
+		Preload("Merchant").Preload("User").
+		Order("merchant_members.merchant_id ASC, merchant_members.id ASC").
+		Find(&members).Error; err != nil {
+		return nil, 0, err
+	}
+
+	groups := make([]MerchantMemberGroup, 0, len(merchantIDs))
+	byMerchantID := make(map[uint]*MerchantMemberGroup, len(merchantIDs))
+	for _, merchantID := range merchantIDs {
+		groups = append(groups, MerchantMemberGroup{MerchantID: merchantID, Members: []model.MerchantMember{}})
+		byMerchantID[merchantID] = &groups[len(groups)-1]
+	}
+	for _, member := range members {
+		group := byMerchantID[member.MerchantID]
+		if group.Merchant == nil {
+			group.Merchant = member.Merchant
+		}
+		group.Members = append(group.Members, member)
+	}
+	return groups, total, nil
+}
+
 // CreatePlatformAdmin creates an account with platform-only privileges. It
 // deliberately does not assign the account to any merchant.
 func (s *UserService) CreatePlatformAdmin(username, password, nickname string) (*model.User, error) {