Feature request: Support white-label OAuth callback domains for custom-domain apps

I would like Base44 to support custom OAuth callback domains for apps using custom domains.

Current behaviour:
When users sign in with Google, the Google Developer info popup shows:

“Choosing an account will redirect you to: https://app.base44.com”

Even when the app name, logo, support email, privacy policy, and terms are fully branded, the OAuth redirect domain still shows Base44’s platform domain.

Requested behaviour:
Allow apps with custom domains to use a branded OAuth callback domain, for example:

https://auth.myapp.com

or:

https://myapp.com/auth/callback

Why this matters:
For customer-facing products, authentication is a high-trust moment. Seeing a different platform domain during Google sign-in can confuse users or reduce confidence, especially for businesses trying to provide a fully branded experience.

Suggested implementation:
Base44 could offer this as an advanced or paid feature where app owners can configure a custom auth callback subdomain, verify DNS, and have Base44 route OAuth callbacks through that branded domain.

Expected benefit:
This would make Base44 apps feel more professional, trustworthy, and fully white-labelled for end users while preserving Base44’s managed authentication infrastructure.