feat(auth): complete registration anti-spam and quota hardening

app/Models/SystemEmailQuota.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class SystemEmailQuota extends Model
+{
+    protected $table = 'system_email_quota';
+
+    public $timestamps = false;
+
+    protected $fillable = [
+        'period',
+        'sent_count',
+        'limit_count',
+        'updated_at',
+    ];
+
+    protected $casts = [
+        'updated_at' => 'datetime',
+        'sent_count' => 'integer',
+        'limit_count' => 'integer',
+    ];
+}
+