refactor(#93): extraire un widget UserList réutilisable

Centralise le pattern d'affichage des listes utilisateurs pour garantir une UI homogène entre gestionnaires, parents, assistantes maternelles et administrateurs.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/widgets/admin/parent_managmant_widget.dart

@@ -2,8 +2,8 @@ import 'package:flutter/material.dart';
 import 'package:p_tits_pas/models/parent_model.dart';
 import 'package:p_tits_pas/services/user_service.dart';
 import 'package:p_tits_pas/widgets/admin/common/admin_detail_modal.dart';
-import 'package:p_tits_pas/widgets/admin/common/admin_list_state.dart';
 import 'package:p_tits_pas/widgets/admin/common/admin_user_card.dart';
+import 'package:p_tits_pas/widgets/admin/common/user_list.dart';
 
 class ParentManagementWidget extends StatefulWidget {
   final String searchQuery;
@@ -65,42 +65,32 @@ class _ParentManagementWidgetState extends State<ParentManagementWidget> {
       return matchesName && matchesStatus;
     }).toList();
 
-    return Padding(
-      padding: const EdgeInsets.all(16),
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          AdminListState(
-            isLoading: _isLoading,
-            error: _error,
-            isEmpty: filteredParents.isEmpty,
-            emptyMessage: 'Aucun parent trouvé.',
-            list: ListView.builder(
-              itemCount: filteredParents.length,
-              itemBuilder: (context, index) {
-                final parent = filteredParents[index];
-                return AdminUserCard(
-                  title: parent.user.fullName,
-                  avatarUrl: parent.user.photoUrl,
-                  subtitleLines: [
-                    parent.user.email,
-                    'Statut : ${_displayStatus(parent.user.statut)} | Enfants : ${parent.childrenCount}',
-                  ],
-                  actions: [
-                    IconButton(
-                      icon: const Icon(Icons.edit),
-                      tooltip: 'Modifier',
-                      onPressed: () {
-                        _openParentDetails(parent);
-                      },
-                    ),
-                  ],
-                );
+    return UserList(
+      isLoading: _isLoading,
+      error: _error,
+      isEmpty: filteredParents.isEmpty,
+      emptyMessage: 'Aucun parent trouvé.',
+      itemCount: filteredParents.length,
+      itemBuilder: (context, index) {
+        final parent = filteredParents[index];
+        return AdminUserCard(
+          title: parent.user.fullName,
+          avatarUrl: parent.user.photoUrl,
+          subtitleLines: [
+            parent.user.email,
+            'Statut : ${_displayStatus(parent.user.statut)} | Enfants : ${parent.childrenCount}',
+          ],
+          actions: [
+            IconButton(
+              icon: const Icon(Icons.edit),
+              tooltip: 'Modifier',
+              onPressed: () {
+                _openParentDetails(parent);
               },
             ),
-          ),
-        ],
-      ),
+          ],
+        );
+      },
     );
   }