Improve admin analytics and user management UI

Refactored admin users page to use client-side fetching, loading states, and search functionality. Enhanced AdminAnalytics with a best month (YTD) card and removed debug logging. Improved SystemStatusCard formatting and removed console logs. Fixed profit chart period selection logic. Minor formatting fix in nav-item component.

components/layout/nav-item.tsx

@@ -65,5 +65,4 @@ export const NavItem: React.FC<NavItemProps> = ({ href, icon: Icon, children, on
       {children}
     </Link>
   )
-}
-
+}