fixed bugs

lib/widgets/app_bottom_nav.dart

@@ -1,15 +1,79 @@
 import 'package:flutter/material.dart';
 
+import '../models/school.dart';
+import '../screens/home_page.dart';
+import '../screens/lessons_page.dart';
+import '../screens/account_page.dart';
+import '../screens/meditation_page.dart';
+
+/// Bottom navigation centralizzata.
+/// Gestisce da sé la navigazione tra le 4 tab principali.
+/// Ogni pagina passa solo il proprio [currentIndex] e i dati utente.
+///
+/// [onBeforeLeave] è opzionale: le pagine che devono fare pulizia prima di
+/// uscire (es. Meditazione che ferma musica/timer) lo passano.
 class AppBottomNav extends StatelessWidget {
   final int currentIndex;
-  final ValueChanged<int> onTap;
+  final String token;
+  final School school;
+  final String? userFirstName;
+  final Future<void> Function()? onBeforeLeave;
 
   const AppBottomNav({
     super.key,
     required this.currentIndex,
-    required this.onTap,
+    required this.token,
+    required this.school,
+    this.userFirstName,
+    this.onBeforeLeave,
   });
 
+  Future<void> _go(BuildContext context, int i) async {
+    if (i == currentIndex) return;
+
+    // pulizia eventuale (musica/timer) prima di lasciare la pagina
+    if (onBeforeLeave != null) {
+      await onBeforeLeave!();
+    }
+    if (!context.mounted) return;
+
+    Widget page;
+    switch (i) {
+      case 0:
+        page = HomePage(
+          token: token,
+          school: school,
+          userFirstName: userFirstName,
+        );
+        break;
+      case 1:
+        page = LessonsPage(
+          token: token,
+          school: school,
+          userFirstName: userFirstName,
+        );
+        break;
+      case 2:
+        page = AccountPage(
+          token: token,
+          school: school,
+          userFirstName: userFirstName,
+        );
+        break;
+      case 3:
+        page = MeditationPage(
+          token: token,
+          school: school,
+          userFirstName: userFirstName,
+        );
+        break;
+      default:
+        return;
+    }
+
+    Navigator.pushReplacement(context, MaterialPageRoute(builder: (_) => page));
+  }
+
   @override
   Widget build(BuildContext context) {
     return BottomNavigationBar(
@@ -18,7 +82,7 @@ class AppBottomNav extends StatelessWidget {
       selectedItemColor: const Color(0xFF10B981),
       unselectedItemColor: Colors.black54,
       currentIndex: currentIndex,
-      onTap: onTap,
+      onTap: (i) => _go(context, i),
       items: const [
         BottomNavigationBarItem(icon: Icon(Icons.home_rounded), label: 'Home'),
         BottomNavigationBarItem(

lib/widgets/app_drawer.dart

@@ -127,7 +127,11 @@ class AppDrawer extends StatelessWidget {
                 Navigator.push(
                   context,
                   MaterialPageRoute(
-                    builder: (_) => OrdersDetailPage(token: token),
+                    builder: (_) => OrdersDetailPage(
+                      token: token,
+                      school: school,
+                      userFirstName: userFirstName,
+                    ),
                   ),
                 );
               },