Add automatic cleanup (cron/Drush) for old spam entities

Add automatic cleanup for old spam entities.

Currently spam entities can accumulate over time and increase database size, which may affect performance. It would be useful to add an option to automatically delete old spam entities.

Proposed solution: add configurable automatic cleanup via cron (with batch processing), optional QueueWorker support for safer processing of large datasets, and a Drush command for manual cleanup (e.g. drush nobotiq:spam-delete). It should also be possible to define retention rules, for example deleting spam older than X days.