fix(android): SetBackground colour doesn't reach the safe areas

[SRWieZ]

What's wrong

On Android, UI.SetBackground doesn't reach the safe areas. In landscape, the strip beside the camera cutout (and behind the navigation bar) keeps the default light background instead of the colour you set. iOS already gets this right.

Why

Android paints the window behind the app, but the screen's container (a Material Scaffold) covers it edge to edge with its own default background.

What this does

The Scaffold uses the SetBackground colour when one is set, and keeps the default otherwise. Nothing changes for apps that never call SetBackground. Android only.

How to reproduce

Open this screen on Android and rotate to landscape.

• Before: a light strip on the cutout side and behind the navigation bar.
• After: dark edge to edge.

// routes/mobile.php
Route::native('/repro/insets', \App\NativeComponents\InsetsBackground::class);

// app/NativeComponents/InsetsBackground.php
namespace App\NativeComponents;

use Illuminate\View\View;
use Native\Mobile\Edge\NativeComponent;

class InsetsBackground extends NativeComponent
{
    public function mount(): void
    {
        nativephp_call('UI.SetBackground', json_encode(['color' => '#18181b']));
    }

    public function render(): View
    {
        return view('native.insets-background');
    }
}

{{-- resources/views/native/insets-background.blade.php --}}
<native:column class="w-full h-full bg-zinc-900 items-center justify-center">
    <native:top-bar title="Insets" :background-color="'#18181b'" :text-color="'#ffffff'" />
    <native:text class="text-[17] text-white">Rotate to landscape</native:text>
</native:column>

[SRWieZ]

Closing in favour of #528, which fixes the same strips the standard way: through the screen's own bg-* class, without calling UI.SetBackground.