`MacosScaffold` should not add a `SizedBox` to the top of `Sidebar` 🐛

[GroovinChip]

Description

Currently, MacosScaffold builds a SizedBox(height: titleBarHeight - 1), and adds it to the top of the sidebar. It results in undesired behavior. See the following screenshot:

Steps To Reproduce

1. Create a new Flutter project and add macos_ui to pubspec.yaml
2. Replace the contents of main.dart with the following:

import 'package:flutter/material.dart';
import 'package:macos_ui/macos_ui.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MacosApp(
      home: MacosHome(),
    );
  }
}

class MacosHome extends StatelessWidget {
  const MacosHome({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MacosScaffold(
      sidebar: Sidebar(
        minWidth: 200,
        maxWidth: 300,
        builder: (context, scrollController) {
          return Column(
            children: [
              Text('Test'),
            ],
          );
        },
      ),
    );
  }
}

Expected behavior

The expected behavior is that Text('Test') should be flush with the window titlebar.

Screenshots

See above

Logs

No logs to report

[GroovinChip]

@lesliearkorful What's the rationale for having this SizedBox at the top of the Sidebar?

[lesliearkorful]

It's the top padding (or safe area) for sidebars when the native title bar is hidden or transparent. That top padding is equal to the height of the title bar in macos

You're seeing it like this because your app is showing the native macos title bar.

I guess we'll need a property to add or remove the top padding for the side bar.

I attached a screenshot of the Apple music app

[GroovinChip]

It happens in projects where I hide the native titlebar as well: