DTO Serialization (Dart Data Class Generator)

When to use

• Creating a new DTO for API/persistence.
• Adding fields that require custom mapping (DateTime, Duration, enums, nested DTOs).
• Enforcing the “no freezed/json_serializable/build_runner for models” policy.

Steps

1) Define the DTO as immutable

Prefer @immutable + class + const constructor:

import 'package:flutter/foundation.dart';