Fix frontend TypeScript compilation errors

- Fix process.env.NODE_ENV in ApplicationInfo.tsx (use import.meta.env.DEV)
- Remove unused variables and imports in Profile.tsx, ProfileSettings.tsx, RoleManagement.tsx, UserManagement.tsx, UserSettings.tsx
- Fix FormData type issue in UserSettings.tsx (use React.FormEvent<HTMLFormElement>)

frontend/src/components/UserManagement.tsx

@@ -32,7 +32,7 @@ export default function UserManagement() {
   const [showPasswordModal, setShowPasswordModal] = useState(false);
   const [selectedUser, setSelectedUser] = useState<User | null>(null);
   const [searchTerm, setSearchTerm] = useState('');
-  const [expandedUser, setExpandedUser] = useState<number | null>(null);
+  // const [expandedUser, setExpandedUser] = useState<number | null>(null); // Unused for now
   const [actionMenuOpen, setActionMenuOpen] = useState<number | null>(null);
 
   const hasManageUsers = useHasPermission('manage_users');