incr/app/Models/Tracker.php

<?php

declare(strict_types=1);

namespace App\Models;

use Database\Factories\TrackerFactory;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Tracker extends Model
{
    /** @use HasFactory<TrackerFactory> */
    use HasFactory;

    protected $fillable = [
        'label',
        'unit',
        'count',
    ];

    protected function casts(): array
    {
        return [
            'count' => 'integer',
        ];
    }

    public static function current(): ?self
    {
        return self::orderBy('id')->first();
    }
}