Verify OAuth token during registration
Verify an OAuth ID token (from Google or Microsoft) as part of the registration flow. On success, returns an `oAuthTokenVerificationRequestId` — pass this in the `/Register` body to skip the email verification step.
**Setup required in the Vlens portal** before using OAuth providers. See the Google Cloud Platform Console and Azure AD B2C documentation for configuring OAuth client credentials.
**Supported providers:**
- **Google** — configure via Google Cloud Platform Console
- **Microsoft** — configure via Azure AD B2C

