refactor: code quality via Rector, strict types where safe

rector.php gets the codeQuality set: declare(strict_types=1) in the 85
files where Rector finds no call relying on scalar type juggling (mostly
TCA and configuration, models, the content feed API and the import
command), "or die" as "|| die", instanceof instead of null checks for
object types, early returns and self:: in final classes.

Hotel::setRooms() goes instead of getting the property Rector wanted to
declare: nothing calls it, and there is no rooms column any more.

Checked locally: cache warmup, the ep:* commands load, frontend crawl
(~1,900 URLs) and the backchannel APIs render the same as before.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/ep_theme/Classes/Domain/Model/Page.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace EP\EpTheme\Domain\Model;
 
 use TYPO3\CMS\Extbase\DomainObject\AbstractEntity;