File: //home/marketing.cfbon.ru/public_html/app/Observers/GalleryObserver.php
<?php
namespace App\Observers;
use App\Http\Requests\Site\GalleryRequest;
use App\Models\Gallery;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Storage;
class GalleryObserver
{
    protected Request $request;
    public function __construct(Request $request)
    {
        $this->request = $request;
    }
    public function created(Gallery $gallery): void
    {
        $this->saveImage($gallery);
    }
    public function updated(Gallery $gallery): void
    {
        if ($this->request->hasFile('img')) {
            $this->deleteOldImage($gallery);
            $this->saveImage($gallery);
        }
    }
    public function deleted(Gallery $gallery): void
    {
        $this->deleteOldImage($gallery);
    }
    private function saveImage(Gallery $gallery): void
    {
        if (! request()->hasFile('img')) {
            return;
        }
        $file = request()->file('img');
        $path = $file->store('gallery', 'public');
        $gallery->forceFill(['img' => $path])->saveQuietly();
    }
    private function deleteOldImage(Gallery $gallery): void
    {
        if ($oldPath = $gallery->getOriginal('img')) {
            Storage::disk('public')->delete($oldPath);
        }
    }
}