POST / with a React server-actions header is not a request this app
makes — TanStack server functions POST to /_serverFn/<id>. Left alone
the transform stream sat open until the 120s lifetime timer force-cleaned
it, surfacing as a fatal uncaught exception in Sentry (event e267e264,
release 84dffa8). Now answered 404 in 9ms; normal pages unaffected.