added attchments

app/Models/AttachmentGroup.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+/**
+ * @property int $id
+ * @property string $name
+ * @property int|null $parent_id
+ * @property int|null $position
+ * @property int $max_size_kb
+ * @property bool $is_active
+ * @mixin \Eloquent
+ */
+class AttachmentGroup extends Model
+{
+    protected $fillable = [
+        'name',
+        'parent_id',
+        'position',
+        'max_size_kb',
+        'is_active',
+    ];
+
+    protected $casts = [
+        'is_active' => 'bool',
+    ];
+
+    public function extensions(): HasMany
+    {
+        return $this->hasMany(AttachmentExtension::class, 'attachment_group_id');
+    }
+
+    public function parent(): BelongsTo
+    {
+        return $this->belongsTo(self::class, 'parent_id');
+    }
+
+    public function children(): HasMany
+    {
+        return $this->hasMany(self::class, 'parent_id');
+    }
+}