feat(100): bandeau dashboard générique, icônes rôle/email, footer go_router, user fromJson défensif

- Bandeau générique DashboardBandeau (logo | onglets | capsule utilisateur)
- Capsule: icône rôle (admin/gestionnaire/parent/AM) + Prénom Nom + menu (email avec icône, Profil, Paramètres, Déconnexion)
- Migration admin, gestionnaire, parent, AM vers DashboardBandeau
- Écran AM (page blanche), route /am-dashboard
- Routes /privacy et /legal, footer avec context.push
- AppUser.fromJson: id/email/role null-safe
- Suppression DashboardAppBarAdmin et dashboard_app_bar.dart

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

frontend/lib/screens/administrateurs/admin_dashboardScreen.dart

@@ -1,9 +1,12 @@
 import 'package:flutter/material.dart';
+import 'package:p_tits_pas/models/user.dart';
+import 'package:p_tits_pas/services/auth_service.dart';
 import 'package:p_tits_pas/services/configuration_service.dart';
+import 'package:p_tits_pas/widgets/admin/dashboard_admin.dart';
 import 'package:p_tits_pas/widgets/admin/parametres_panel.dart';
 import 'package:p_tits_pas/widgets/admin/user_management_panel.dart';
 import 'package:p_tits_pas/widgets/app_footer.dart';
-import 'package:p_tits_pas/widgets/admin/dashboard_admin.dart';
+import 'package:p_tits_pas/widgets/dashboard/dashboard_bandeau.dart';
 
 class AdminDashboardScreen extends StatefulWidget {
   const AdminDashboardScreen({super.key});
@@ -14,6 +17,7 @@ class AdminDashboardScreen extends StatefulWidget {
 
 class _AdminDashboardScreenState extends State<AdminDashboardScreen> {
   bool? _setupCompleted;
+  AppUser? _user;
   int mainTabIndex = 0;
   int settingsSubIndex = 0;
 
@@ -31,9 +35,11 @@ class _AdminDashboardScreenState extends State<AdminDashboardScreen> {
   Future<void> _loadSetupStatus() async {
     try {
       final completed = await ConfigurationService.getSetupStatus();
+      final user = await AuthService.getCurrentUser();
       if (!mounted) return;
       setState(() {
         _setupCompleted = completed;
+        _user = user;
         if (!completed) mainTabIndex = 1;
       });
     } catch (e) {
@@ -68,17 +74,29 @@ class _AdminDashboardScreenState extends State<AdminDashboardScreen> {
     return Scaffold(
       appBar: PreferredSize(
         preferredSize: const Size.fromHeight(60.0),
-        child: Container(
-          decoration: BoxDecoration(
-            border: Border(
-              bottom: BorderSide(color: Colors.grey.shade300),
+        child: DashboardBandeau(
+          tabItems: [
+            DashboardTabItem(
+              label: 'Gestion des utilisateurs',
+              enabled: _setupCompleted!,
             ),
-          ),
-          child: DashboardAppBarAdmin(
-            selectedIndex: mainTabIndex,
-            onTabChange: onMainTabChange,
-            setupCompleted: _setupCompleted!,
-          ),
+            const DashboardTabItem(label: 'Paramètres'),
+          ],
+          selectedTabIndex: mainTabIndex,
+          onTabSelected: onMainTabChange,
+          userDisplayName: _user?.fullName.isNotEmpty == true
+              ? _user!.fullName
+              : 'Admin',
+          userEmail: _user?.email,
+          userRole: _user?.role,
+          onProfileTap: () {
+            ScaffoldMessenger.of(context).showSnackBar(
+              const SnackBar(content: Text('Modification du profil – à venir')),
+            );
+          },
+          onSettingsTap: () => onMainTabChange(1),
+          onLogout: () {},
+          showLogoutConfirmation: true,
         ),
       ),
       body: Column(