Hidden participants (#4)

* add hidden field

* add hidden to participant info

* add comment

* move hidden

auth/grants.go

@@ -14,6 +14,9 @@ type VideoGrant struct {
 	// it's interpreted as both are permissible
 	CanPublish   bool `json:"canPublish,omitempty"`
 	CanSubscribe bool `json:"canSubscribe,omitempty"`
+
+	// used for recording
+	Hidden bool `json:"hidden,omitempty"`
 }
 
 type ClaimGrants struct {

livekit_models.proto

@@ -36,6 +36,8 @@ message ParticipantInfo {
   string metadata = 5;
   // timestamp when participant joined room
   int64 joined_at = 6;
+  // hidden participant (used for recording)
+  bool hidden = 7;
 }
 
 enum TrackType {