refactor: sanitize session variables

[deepsource-dev-autofix]

This PR refactors the way session variables for queue sorting are assigned by adding proper input validation and sanitization.

• Trust Boundary Violation in Session Variables: Previously, the code directly assigned raw $_GET['sort'] and $_GET['dir'] values into the session, creating a trust boundary violation where untrusted user input could persist across requests. The update applies filter_input with FILTER_SANITIZE_STRING to clean the 'sort' parameter and then checks it against a whitelist ($queue_sort_options), defaulting to the first allowed option if the provided value is invalid. For 'dir', it uses FILTER_VALIDATE_INT and forces the value to either 0 or 1, ensuring only expected integers are stored. Note: this implementation assumes that $queue_sort_options[0] is the correct default sort order—please review and adjust if a different default is required.

This Autofix was generated by AI. Please review the change before merging.