fixed shopkeepers at the suggestion of @blablubbabc by ensuring only the client sees the nbt change, where the server will not see any change, by cloning all items before modification on outgoing packets. previously, on some occasions the item would still be modified serverside. this would create different nbt data on items in some cases but not others, creating inconsistencies and making items not actually equal, such as the case for advanced villagers (shopkeeprs plugin) buying weapons (the items are identical but one has hideflags tag and the other doesnt because of my plugin, preventing the trade). my plugin design already had cloning support, just wasn't using it until now. should fix the shopkeepers bug, but i didnt test it myself. if a shopkeepers user runs into more issues, just post in the discussions or on the github