How do I get rid of orphaned variables?

I’ve got four variable collections from unsubscribed, deprecated libraries that remain offerable in a file's variable MODE picker, with zero remaining consumers. They do not appear in the fill or colour picker. There is no UI affordance or plugin API to purge them.

A designer can still apply a mode from a deprecated library, silently reintroducing a dependency on a dead token system. Nothing currently consumes these, so the file will not regress on its own.

Claude says, “Needs a Figma-side fix.” Any suggestions?