Refactor management components to remove loading state: Eliminate unused loading state and related conditional rendering from ChallengeManagement, EventManagement, FeedbackManagement, HouseManagement, and UserManagement components, simplifying the code and improving readability.

components/admin/UserManagement.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState, useEffect, useTransition } from "react";
+import { useState, useTransition } from "react";
 import {
   Avatar,
   Input,
@@ -43,7 +43,6 @@ interface UserManagementProps {
 
 export default function UserManagement({ initialUsers }: UserManagementProps) {
   const [users, setUsers] = useState<User[]>(initialUsers);
-  const [loading, setLoading] = useState(false);
   const [editingUser, setEditingUser] = useState<EditingUser | null>(null);
   const [saving, setSaving] = useState(false);
   const [deletingUserId, setDeletingUserId] = useState<string | null>(null);
@@ -183,10 +182,6 @@ export default function UserManagement({ initialUsers }: UserManagementProps) {
       ? Math.max(0, currentEditingUserData.xp + editingUser.xpDelta)
       : 0;
 
-  if (loading) {
-    return <div className="text-center text-gray-400 py-8">Chargement...</div>;
-  }
-
   return (
     <div className="space-y-4">
       {users.length === 0 ? (