Decouple credentials needed for metrics from the authenticated user.

When custom authorization criteria are provided by env variable, application should use GitHub App and Key to authenticate to GH and get metrics.

Nuxt already supports many modern IDPs (identification providers) https://github.com/sidebase/nuxt-auth hence it should be used to authenticate the users.

One simple way to Authorize the users authenticated by GitHub would be to read coma separate list of usernames from env variable or check group membership.

Propose detailed solution before implementing.