add MemberId to init.

internal/types/message/messages.go

@@ -11,6 +11,7 @@ type Message struct {
 
 type SystemInit struct {
 	Event           string           `json:"event,omitempty"`
+	MemberId        string           `json:"member_id"`
 	ControlHost     ControlHost      `json:"control_host"`
 	ScreenSize      ScreenSize       `json:"screen_size"`
 	Members         []MemberData     `json:"members"`

internal/websocket/handler/system.go

@@ -35,6 +35,7 @@ func (h *MessageHandlerCtx) systemInit(session types.Session) error {
 	return session.Send(
 		message.SystemInit{
 			Event:       event.SYSTEM_INIT,
+			MemberId:    session.ID(),
 			ControlHost: controlHost,
 			Members:     members,
 			ScreenSize:  message.ScreenSize{