Dry run first, always

• Cleanup rules have Dry run only, a safe mode that never deletes or unmonitors. It is off on a new rule, so turn it on yourself. The rule reports what it would do, and those pretend-processed items show on the Dashboard tagged DRY RUN.
• Arr rules have Preview, which is always a dry run. A new rule starts disabled, and its first Apply acts for real, so read its Preview first. A run over its max-changes cap applies the first N and leaves the rest for later.
• Library operations report how many titles each operation would change before anything is written to Plex.