add default native menu osx.
MODIFY
WalletWasabi.Fluent/App.xaml
WalletWasabi.Fluent/App.xaml
<StyleInclude Source="avares://WalletWasabi.Fluent/Controls/NavBarItem.xaml" />
<StyleInclude Source="avares://WalletWasabi.Fluent/Controls/NavBarTreeItem.xaml" />
</Application.Styles>
+ <NativeMenu.Menu>
+ <NativeMenu>
+ <NativeMenuItem Header="About Wasabi Wallet" Command="{Binding AboutCommand}" />
+ </NativeMenu>
+ </NativeMenu.Menu>
</Application>

add default native menu osx.