add screencast enabled bool to system init.

internal/types/message/messages.go

@@ -27,6 +27,7 @@ type SystemInit struct {
 	ScreenSize        ScreenSize             `json:"screen_size"`
 	Sessions          map[string]SessionData `json:"sessions"`
 	ImplicitHosting   bool                   `json:"implicit_hosting"`
+	ScreencastEnabled bool                   `json:"screencast_enabled"`
 	WebRTC            SystemWebRTC           `json:"webrtc"`
 }
 

internal/websocket/handler/system.go

@@ -45,6 +45,7 @@ func (h *MessageHandlerCtx) systemInit(session types.Session) error {
 			},
 			Sessions:          sessions,
 			ImplicitHosting:   h.sessions.ImplicitHosting(),
+			ScreencastEnabled: h.capture.Screencast().Enabled(),
 			WebRTC: message.SystemWebRTC{
 				Videos: h.capture.VideoIDs(),
 			},