Unification and flexibility with `AUTH_ORIGIN`

[hywax]

Describe the feature

What problems there are now:

• Hardcode variable AUTH_ORIGIN. Not all projects are suitable for this name. For example, if the project uses NuxtSEO, then SITE_URL should be specified there too, which in turn is equal to AUTH_ORIGIN. If AUTH_ORIGIN could be changed, then one variable would be used.
• It conflicts with Nuxt. Since Nuxt uses the NUXT_ prefix (which can be changed).

How would you implement this?

1) Switch completely to useRuntimeConfig(). This will get rid of naming inconsistencies 2) Add to nuxt.config the ability to set the variable dynamically

An example of how it will look like: nuxt.config.ts

export default defineNuxtConfig({
  runtimeConfig: {
    authOrigin: '',
  },
  auth: {
    originEnvKey: 'AUTH_ORIGIN' // by default
  }
})

.env

NUXT_AUTH_ORIGIN=https://my.app

Additional information

• [X] Would you be willing to help implement this feature?

Provider

• [x] AuthJS
• [ ] Local
• [ ] Refresh
• [ ] New Provider