Describe the feature

Refering to runtime configuration , I think that the current implementation (runtime variables will be overriden by NUXT_ prefixed environmental viariables) is kind of ugly.
The problem is that one may already have some env vars, e.g. (DB_URL), that might live in a common env file that is shared among many applications. With the current implementation we have to "pollute" the env file with duplicate definitions (e.g. add the NUXT_DB_URL in addition to the already existing, duplicating the variable content as well).

While, nuxt could just have a semantic to resolve arbitrary env vars (at runtime). e.g.

export default defineNuxtConfig({
  runtimeConfig: {
    apiSecret: '${APP_SECRET}' // This resolves the environment variable APP_SECRET at runtime

Using

nuxt version 3.6.5

Additional information

• Would you be willing to help implement this feature?
• Could this feature be implemented as a module?

Final checks

• Read the contribution guide.
• Check existing discussions and issues.