🚸(frontend) notify all participants when recording/transcription stops

Broadcast limit-reached notifications to all room participants, not just
owner, to ensure everyone knows recording has stopped due to duration
limits.

src/frontend/src/features/notifications/components/ToastMessageReceived.tsx

@@ -27,7 +27,7 @@ export function ToastMessageReceived({ state, ...props }: ToastProps) {
     }
   }, [isChatOpen, toast, state])
 
-  if (isChatOpen) return null
+  if (isChatOpen || !participant) return null
 
   return (
     <StyledToastContainer {...toastProps} ref={ref}>