remove voice code make optimizations. Fix channels race conditions. add reply function

lib/utils/disconnect_navigation_mixin.dart

@@ -0,0 +1,20 @@
+import 'package:flutter/material.dart';
+import '../connector/meshcore_connector.dart';
+
+/// Mixin that automatically navigates back to scanner when disconnected.
+/// Use in State classes for screens that require active connection.
+mixin DisconnectNavigationMixin<T extends StatefulWidget> on State<T> {
+  /// Call this in your Widget build method to enable auto-navigation.
+  /// Returns true if still connected, false if navigation was triggered.
+  bool checkConnectionAndNavigate(MeshCoreConnector connector) {
+    if (!connector.isConnected) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (mounted) {
+          Navigator.popUntil(context, (route) => route.isFirst);
+        }
+      });
+      return false;
+    }
+    return true;
+  }
+}