feat(auth): harden authentication and add configurable two-factor support

app/Notifications/PasswordChangedNotification.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace App\Notifications;
+
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Messages\MailMessage;
+use Illuminate\Notifications\Notification;
+
+class PasswordChangedNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    public function __construct(
+        public readonly string $ipAddress,
+        public readonly string $occurredAt
+    ) {}
+
+    /**
+     * @return list<string>
+     */
+    public function via(object $notifiable): array
+    {
+        return ['mail'];
+    }
+
+    public function toMail(object $notifiable): MailMessage
+    {
+        return (new MailMessage)
+            ->subject('Your password was changed')
+            ->greeting('Hello '.$notifiable->first_name.',')
+            ->line('The password for your account was changed.')
+            ->line("Time: {$this->occurredAt}")
+            ->line("IP address: {$this->ipAddress}")
+            ->line('All other signed-in sessions have been ended.')
+            ->line('If you did not make this change, contact support immediately.');
+    }
+}