feat(#160): suppressions dashboard — poubelle, confirmations et sans_enfant.

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

frontend/lib/widgets/admin/relais_management_panel.dart

@@ -3,6 +3,7 @@ import 'package:flutter/services.dart';
 import 'package:p_tits_pas/models/relais_model.dart';
 import 'package:p_tits_pas/utils/phone_utils.dart';
 import 'package:p_tits_pas/services/relais_service.dart';
+import 'package:p_tits_pas/widgets/admin/common/suppression_confirm_dialog.dart';
 
 class RelaisManagementPanel extends StatefulWidget {
   const RelaisManagementPanel({super.key});
@@ -56,28 +57,16 @@ class _RelaisManagementPanelState extends State<RelaisManagementPanel> {
     try {
       if (result.action == _RelaisDialogAction.delete) {
         if (relais == null) return;
-        final confirmed = await showDialog<bool>(
-          context: context,
-          builder: (ctx) => AlertDialog(
-            title: const Text('Supprimer le relais'),
-            content: Text('Confirmer la suppression de "${relais.nom}" ?'),
-            actions: [
-              TextButton(
-                onPressed: () => Navigator.of(ctx).pop(false),
-                child: const Text('Annuler'),
-              ),
-              FilledButton(
-                onPressed: () => Navigator.of(ctx).pop(true),
-                style: FilledButton.styleFrom(
-                  backgroundColor: Colors.red.shade700,
-                ),
-                child: const Text('Supprimer'),
-              ),
-            ],
-          ),
+        final confirmed = await showSuppressionConfirmDialog(
+          context,
+          title: 'Supprimer le relais',
+          people: [SuppressionPersonLine.relais(relais.nom)],
+          footnotes: const [
+            'Cette action est irréversible.',
+          ],
         );
 
-        if (confirmed != true) return;
+        if (!confirmed) return;
         await RelaisService.deleteRelais(relais.id);
       } else if (relais == null) {
         await RelaisService.createRelais(result.payload!);