Activate vanity subdomain for project
Activates a vanity subdomain for the specified Supabase project (e.g., 'my-brand.supabase.co'). Important notes: - Vanity subdomains require a paid plan (Pro/Team/Enterprise) - Usage of vanity subdomains and custom domains is mutually exclusive - After activation, your project's auth services will no longer work on the original {project-ref}.supabase.co hostname - Schedule a downtime window to update client code and OAuth providers before activating