feat: show when there is an active huddle

This introduces a webhook which listens to events from livekit and
updates our firestore stream particle. It keeps the client simple,
reacting to changes to firestore docs.

go/internal/particle/firestore_types.go

@@ -46,8 +46,9 @@ type FirestoreStreamParticle struct {
 	CreatedByHumanId string `firestore:"created_by_human_id"`
 	Type             string `firestore:"type"`
 	// Properties       FirestoreStreamParticleProperties `firestore:"properties"`
-	CreatedAt          time.Time  `firestore:"created_at,serverTimestamp"`
-	LastChildCreatedAt *time.Time `firestore:"last_child_created_at,omitempty"`
-	VisibleTo          []string   `firestore:"visible_to"`
-	UpdatedAt          *time.Time `firestore:"updated_at,omitempty"`
+	CreatedAt                time.Time  `firestore:"created_at,serverTimestamp"`
+	LastChildCreatedAt       *time.Time `firestore:"last_child_created_at,omitempty"`
+	VisibleTo                []string   `firestore:"visible_to"`
+	UpdatedAt                *time.Time `firestore:"updated_at,omitempty"`
+	HuddleActiveParticipants []string   `firestore:"huddle_active_participants,omitempty"`
 }