chore: override nanoid@3 to fix Dependabot alert (#471)

`hypertune` and `@vercel/microfrontends` resolved to nanoid 3.3.16, which
is vulnerable to an infinite loop when a custom generator is called with
size zero. The existing `nanoid@>=4` override did not cover the v3 range,
so add a matching `nanoid@3: ^3.3.18` override.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>