Moves the three clone-* handlers (--clone-quest,
--clone-creature, --clone-object) out of main.cpp into a new
cli_clone.{hpp,cpp} module. All three deep-copy by index,
optionally rename, and (for creature/object) offset the new
copy by 5 yards along X to prevent z-fighting with the
original. Each resets the per-entity unique id so downstream
systems that dedupe by id stay consistent.
main.cpp shrinks by 184 lines (6,315 to 6,131).
