* extend tests
* more tests for world save
* explicit handle the special layers in wornitem
* add Location variant and relocate() methods
* refactor GottenItem and ensure Chr, not wornitems, is saved
* deflake escript watch test
* dropitem and undo refactoring
* uomod changes
* add more item tests (buy, sell, hair...)
* use location for undoing trade container properly
* rewrite loaddata to use relocate, fixing startup crashes
* do remaining location changes
* fix CI tests
* remove container pointer from item and add wearer() reference
* remove layer writes and explicit intrinsic weapon handling
* add preparing state for fresh items without serial number
* move wornitems to detached state only when it has a serial number
* load corpse items into the correct layer
* do not set a layer on load before the item is equipped
* add more tests to equipped and intrinsic items
* remove layer and substitute with the location()
* add core-changes summary
* mark items as being worn on corpse if they only moved within the corpse
* block Preparing from being reached, just to be sure
* added integrity sweep check
* Reduce direect changes to item location
* Add Item::move_into() and rewrite calling sites
* Fix container slots
* get rid of the slot_index on the item, because Location() already has it
* fix race in test leading to macos issues
* fix dangling pointer
* remove corpse can_equip_list and rely on the GottenItem rules to dress the corpse again
* let item->destroy() detach the item
* make integrity checks fail the tests
* use place_at(item, newpos) for changing item position InWorld
* add boat test for item moved out of boat that should not be visible anymore
* use place_at() in more places
* ensure CreateItemAtLocation really does
* fix Claude instructions
* remove state we didn't need
* fine tuning
* reduce test flakiness
