feat(auth): block admin login IP after 4 failures for 20 min, email login alerts

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Mail/Admin/AdminLoginAlertMail.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Mail\Admin;
+
+use App\Mail\TemplateMailable;
+use Illuminate\Bus\Queueable;
+
+class AdminLoginAlertMail extends TemplateMailable
+{
+    use Queueable;
+
+    /**
+     * @param array{admin_name: string, admin_username: string, login_time: string, client_ip: string, user_agent: string} $data
+     */
+    public function __construct(public array $data) {}
+
+    protected function scenario(): string
+    {
+        return 'admin_login_alert';
+    }
+
+    protected function variables(): array
+    {
+        return $this->data;
+    }
+}