audit entries hardcoded actor: 'admin' regardless of who performed the
action. Both local gateways now pull the signed-in admin's displayName
from AdminAuthService, falling back to 'admin' only when unavailable.
Moderation's actor field is a role classifier ('admin' | 'customer'),
not an identity string, and is left unchanged.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>