added attchments

app/Models/AttachmentExtension.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+/**
+ * @property int $id
+ * @property string $extension
+ * @property int|null $attachment_group_id
+ * @property array|null $allowed_mimes
+ * @mixin \Eloquent
+ */
+class AttachmentExtension extends Model
+{
+    protected $fillable = [
+        'extension',
+        'attachment_group_id',
+        'allowed_mimes',
+    ];
+
+    protected $casts = [
+        'allowed_mimes' => 'array',
+    ];
+
+    public function group(): BelongsTo
+    {
+        return $this->belongsTo(AttachmentGroup::class, 'attachment_group_id');
+    }
+}