feat(agents): align update validation errors

internal/service/agent_service.go

@@ -23,6 +23,8 @@ type AgentService struct {
 	db        *gorm.DB
 }
 
+var ErrAgentNameBlank = errors.New("agent name cannot be blank")
+
 // NewAgentService creates a new Agent service.
 func NewAgentService(agentRepo *repository.AgentRepo, db *gorm.DB) *AgentService {
 	return &AgentService{agentRepo: agentRepo, db: db}
@@ -54,6 +56,7 @@ type UpdateAgentRequest struct {
 	Availability   string `json:"availability,omitempty" validate:"omitempty,oneof=online offline busy"`
 	AutoOffline    bool   `json:"auto_offline"`
 	CustomRoleID   *uint  `json:"custom_role_id,omitempty"`
+	nameSet        bool
 	autoOfflineSet bool
 	customRoleSet  bool
 }
@@ -69,11 +72,13 @@ func (r *UpdateAgentRequest) UnmarshalJSON(data []byte) error {
 		return err
 	}
 	*r = UpdateAgentRequest(decoded)
+	_, r.nameSet = raw["name"]
 	_, r.autoOfflineSet = raw["auto_offline"]
 	_, r.customRoleSet = raw["custom_role_id"]
 	return nil
 }
 
+func (r UpdateAgentRequest) NameSet() bool         { return r.nameSet }
 func (r UpdateAgentRequest) AutoOfflineSet() bool  { return r.autoOfflineSet }
 func (r UpdateAgentRequest) CustomRoleIDSet() bool { return r.customRoleSet }
 
@@ -134,6 +139,9 @@ func (s *AgentService) Update(ctx context.Context, userID, accountID uint, req U
 	if err := pkgvalidator.ValidateStruct(req); err != nil {
 		return nil, fmt.Errorf("validation: %w", err)
 	}
+	if req.NameSet() && strings.TrimSpace(req.Name) == "" {
+		return nil, ErrAgentNameBlank
+	}
 
 	return s.agentRepo.UpdateAgent(ctx, userID, accountID, req.Name, req.Role, req.Availability, req.AutoOffline, req.AutoOfflineSet(), req.CustomRoleID, req.CustomRoleIDSet())
 }