feat(#96): finaliser la modale admin/gestionnaire et les règles d’édition

Unifie la modale utilisateur pour création/édition admin et gestionnaire, fiabilise la saisie/normalisation (téléphone, nom/prénom) et corrige la mise à jour backend pour accepter le rattachement relais sans erreur 400.

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

frontend/lib/widgets/admin/admin_management_widget.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:p_tits_pas/models/user.dart';
+import 'package:p_tits_pas/screens/administrateurs/creation/gestionnaires_create.dart';
 import 'package:p_tits_pas/services/user_service.dart';
 import 'package:p_tits_pas/widgets/admin/common/admin_user_card.dart';
 import 'package:p_tits_pas/widgets/admin/common/user_list.dart';
@@ -51,6 +52,23 @@ class _AdminManagementWidgetState extends State<AdminManagementWidget> {
     }
   }
 
+  Future<void> _openAdminEditDialog(AppUser user) async {
+    final changed = await showDialog<bool>(
+      context: context,
+      barrierDismissible: false,
+      builder: (dialogContext) {
+        return AdminUserFormDialog(
+          initialUser: user,
+          adminMode: true,
+          withRelais: false,
+        );
+      },
+    );
+    if (changed == true) {
+      await _loadAdmins();
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     final query = widget.searchQuery.toLowerCase();
@@ -80,7 +98,7 @@ class _AdminManagementWidgetState extends State<AdminManagementWidget> {
               icon: const Icon(Icons.edit),
               tooltip: 'Modifier',
               onPressed: () {
-                // TODO: Modifier admin
+                _openAdminEditDialog(user);
               },
             ),
           ],

frontend/lib/widgets/admin/gestionnaire_management_widget.dart

@@ -59,7 +59,7 @@ class _GestionnaireManagementWidgetState
       context: context,
       barrierDismissible: false,
       builder: (dialogContext) {
-        return GestionnaireCreateDialog(initialUser: user);
+        return AdminUserFormDialog(initialUser: user);
       },
     );
     if (changed == true) {

frontend/lib/widgets/admin/user_management_panel.dart

@@ -17,6 +17,7 @@ class AdminUserManagementPanel extends StatefulWidget {
 class _AdminUserManagementPanelState extends State<AdminUserManagementPanel> {
   int _subIndex = 0;
   int _gestionnaireRefreshTick = 0;
+  int _adminRefreshTick = 0;
   final TextEditingController _searchController = TextEditingController();
   final TextEditingController _amCapacityController = TextEditingController();
   String? _parentStatus;
@@ -150,6 +151,7 @@ class _AdminUserManagementPanelState extends State<AdminUserManagementPanel> {
         );
       case 3:
         return AdminManagementWidget(
+          key: ValueKey('admins-$_adminRefreshTick'),
           searchQuery: _searchController.text,
         );
       default:
@@ -176,31 +178,52 @@ class _AdminUserManagementPanelState extends State<AdminUserManagementPanel> {
   }
 
   Future<void> _handleAddPressed() async {
-    if (_subIndex != 0) {
-      if (!mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(
-          content: Text(
-            'La création est disponible uniquement pour les gestionnaires.',
-          ),
-        ),
+    if (_subIndex == 0) {
+      final created = await showDialog<bool>(
+        context: context,
+        barrierDismissible: false,
+        builder: (dialogContext) {
+          return const AdminUserFormDialog();
+        },
       );
+
+      if (!mounted) return;
+      if (created == true) {
+        setState(() {
+          _gestionnaireRefreshTick++;
+        });
+      }
       return;
     }
 
-    final created = await showDialog<bool>(
-      context: context,
-      barrierDismissible: false,
-      builder: (dialogContext) {
-        return const GestionnaireCreateDialog();
-      },
-    );
+    if (_subIndex == 3) {
+      final created = await showDialog<bool>(
+        context: context,
+        barrierDismissible: false,
+        builder: (dialogContext) {
+          return const AdminUserFormDialog(
+            adminMode: true,
+            withRelais: false,
+          );
+        },
+      );
+
+      if (!mounted) return;
+      if (created == true) {
+        setState(() {
+          _adminRefreshTick++;
+        });
+      }
+      return;
+    }
 
     if (!mounted) return;
-    if (created == true) {
-      setState(() {
-        _gestionnaireRefreshTick++;
-      });
-    }
+    ScaffoldMessenger.of(context).showSnackBar(
+      const SnackBar(
+        content: Text(
+          'La création est disponible pour les gestionnaires et administrateurs.',
+        ),
+      ),
+    );
   }
 }