before-user-created webhook sends different ID than is actually solved in Auth for SSO providers

# Bug report - [ x] I confirm this is a bug with Supabase, not with my own application. - [ x] I confirm I have searched the [Docs](https://docs.supabase.com), GitHub [Discussions](https://github.com/supabase/supabase/discussions), and [Discord](https://discord.supabase.com). ## Describe the bug The before-user-created Auth Hook sends a different user.id in the webhook payload than what Supabase Auth actually stores in auth.users when users sign up via OAuth/SSO providers (confirmed with Google OAuth). This makes the webhook unreliable for its primary use case: creating related records (e.g., profiles) with foreign key relationships to auth.users.id. ## To Reproduce 1. Configure a before-user-created webhook endpoint per [docs](https://supabase.com/docs/guides/auth/auth-hooks/before-user-created-hook) 2. In your webhook handler, log or store the user.id from the payload 3. Sign up a new user using Google OAuth 4. Query auth.users for the newly created user 5. Compare the id from the webhook payload with the id in auth.users 6. Observe they do not match Note: Email+password signup works correctly—the IDs match. The issue only occurs with OAuth/SSO providers. ## Expected behavior The user.id provided in the before-user-created webhook payload should match the id that gets stored in auth.users, regardless of the authentication method used.