Exercises Sync-ManagedDestination directly against a throwaway
source/destination pair: idempotent second install (no writes, no
backups), removal of a stale-and-untouched file, protection of a
stale-but-locally-modified file (backed up, left in place, warned), a
foreign file that was never installed staying untouched, and a dry run
that reports the planned removal without any side effects.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
