Creates 7 files: useAdmin hook with TanStack Query v5, AdminPortal
layout with horizontal tab nav, IAMPage with user table + stat cards
+ system settings, UserActionsMenu with two-click confirms, CreateUserDialog,
ConfigPage with paginated audit log + action filter, AdminDashboardPage
with stats + recent logins/actions tables.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
