[v1.0.0-beta.3] isPackageExists broken and doesn't detect local @mdi/fonts package anymore

[Q16solver]

Hi!

I noticed this issue appeared since I have CSP policies that prevent external non-whitelisted urls and found the vuetify was going to cdn for icons now even though @mdi/fonts was installed locally, this is after updating from beta.2 to beta.3, claude analysis if it helps

@mdi/font is already a local dependency — the module just broke its isPackageExists() check between versions, causing it to fall
  back to the CDN URL. The new version from main should auto-detect the local package again and serve it without any CDN.

  Updating security.ts to allow https://cdn.jsdelivr.net would be treating the symptom — it'd also mean an unnecessary external
  request on every load.

[AndreyYolkin]

Rolled back in 1cedac1