Is there something else I need to do register the view for auth_callback that I may be missing?

Yes.. I made sure the permissions were identical to login.php (which works), but I still see the permission error in the error log.  

-rwxr-xr-x. 1 apache apache 1426 Nov 5 17:36 auth_callback.php

-rwxr-xr-x. 1 apache apache 1432 Nov 5 14:59 login.php

I don't know :) You can do almost everything

Elgg version?

2

You can use Search Advanced plugin to add 'Search' widget on your index page.

Or use the custom search form:

$form_body .= elgg_view('input/submit', ['value' => elgg_echo('search')]);

$form_options = [
     'body' => $form_body,
     'action' => '/search',
     'disable_security' => true
];

echo elgg_view('input/form', $form_options);

Or extend your index page:

elgg_extend_view('resources/my_index', 'search/search_box');

Changing the ScraperService.php of this part:

$qb = Insert::intoTable('scraper_data');
$qb->setValue('url', $qb->param($url, ELGG_VALUE_STRING))
->setValue('hash', $qb->param(sha1($url), ELGG_VALUE_STRING))
->setValue('data', $qb->param(serialize($data)));

$result = $this->db->insertData($qb);

$dbprefix = elgg_get_config('dbprefix');
$query = "
INSERT INTO {$dbprefix}scraper_data
SET url = :url,
    hash = :hash,
    data = :data
ON DUPLICATE KEY UPDATE
    data = :data
";

$result = $this->db->insertData($query, [
   ':url' => (string) $url,
   ':data' => serialize($data),
   ':hash' => sha1($url),
]);

Made me happy to, thanks a lot :-)