[Feature]: OIDC custom scopes

[moonlight8978]

Feature Summary

Allow user to custom OIDC scopes for authentication

What problem does this feature solve?

I'm using Zitadel for OIDC, and I'd like to use urn:zitadel:iam:org:id:{id} as extra scope, so Zitadel can correctly show my org login page instead of the default one
https://zitadel.com/docs/apis/openidoauth/scopes

but currently, the scopes are hard-coded inside source code

v2/internal/oauth2/oidc.go

Line 51 in 86fca5d

Scopes: []string{oidc.ScopeOpenID, "profile", "email"},

Is there any chances of support custom scopes for OIDC? I can make a PR for it.

Proposed Solution

Support an optional environment variable like OAUTH2_SCOPES

Alternatives Considered

No response

Additional Context

No response

Checklist

• I have searched existing issues to ensure this feature hasn't been requested before.
• I understand that feature requests are not guaranteed to be implemented.
• I agree to follow the project's contribution guidelines.