LaravelApp/app/Models/Attachment.php

<?php

namespace App\Models;

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

class Attachment extends Model
{
    use HasFactory;

    protected $fillable = [
        'attachable_type',
        'attachable_id',
        'filename',
        'filepath',
        'mime_type',
        'size',
    ];

    protected $casts = [
        'size' => 'integer',
        'created_at' => 'datetime',
        'updated_at' => 'datetime',
    ];

    // Полиморфная связь: вложение может принадлежать разным моделям
    public function attachable()
    {
        return $this->morphTo();
    }
}