hive-matrix: refresh stale bindMounts comment after activation-script fix (argus)

nix/modules/hive-matrix.nix

@@ -209,10 +209,10 @@ in
       privateNetwork = false;
       # Read-only bind of the host-managed registration token so
       # tuwunel can resolve `registration_token_file` to a real
-      # file inside the container. The host path doesn't need to
-      # exist at eval time (the file is generated by hive-c0re's
-      # `matrix::ensure_register_token` on first boot); nspawn will
-      # create the bind mount on container start either way.
+      # file inside the container. The activation script above
+      # ensures the host path exists with a valid 64-char hex token
+      # before any container starts, so the bind always finds real
+      # content (no first-boot empty-file race; argus #565 nit).
       bindMounts.${cfg.registrationTokenFile} = {
         hostPath = cfg.registrationTokenFile;
         isReadOnly = true;