PHPMailer setup and test

1. Install PHPMailer via Composer in the project root:

```bash
cd c:/xampp/htdocs/wi
composer require phpmailer/phpmailer
```

2. Configure SMTP creds (one of):

- Set environment variables: `FLEET_SMTP_HOST`, `FLEET_SMTP_PORT`, `FLEET_SMTP_USER`, `FLEET_SMTP_PASS`, `FLEET_SMTP_SECURE`.
- Or add them to `config/alerts.php` as `smtp_host`, `smtp_port`, `smtp_user`, `smtp_pass`, `smtp_secure`.

3. Run the test script from CLI or browser:

CLI:

```bash
php scripts/test_mail.php
```

Browser:

- Visit `http://localhost/wi/scripts/test_mail.php` (update host/path as needed)

Notes:

- If PHPMailer is not installed, the helper falls back to `mail()`.
- On XAMPP/Windows, ensure `sendmail` or SMTP is configured if relying on `mail()`.
