check for canonicalurl instead of expecting it to be there

pkg/director/stream_session.go

···
 		return fmt.Errorf("livestream is not a streamplace livestream")
 	}
 
+	canonicalUrl := fmt.Sprintf("https://%s/%s", ss.cli.PublicHost, repo.Handle)
+
+	if lsr.CanonicalUrl != nil {
+		canonicalUrl = *lsr.CanonicalUrl
+	}
+
 	actorStatusEmbed := bsky.ActorStatus_Embed{
 		EmbedExternal: &bsky.EmbedExternal{
 			External: &bsky.EmbedExternal_External{
 				Title:       lsr.Title,
-				Uri:         *lsr.CanonicalUrl,
+				Uri:         canonicalUrl,
 				Description: fmt.Sprintf("@%s is 🔴LIVE on %s", repo.Handle, ss.cli.PublicHost),
 				Thumb:       thumb,
 			},