500 LogicSwapSpellsCommand does the real work, 520 and 521 are no-ops in this
build so they just decode. 535 puts its data reference BEFORE the base header,
unlike every other command.
collection only shrinks when a card moves into an empty deck slot, that is the
one case where the home checksum moves.
rounding is banded and the 5s band biases +3, so 22 goes to 25 not 20. numbers match the csv for arena 1 and 2.
free chest end timestamp needs migration 0002.
if the client presents an id we don't know, create it under that id and bump the sequence past it.
also chest offers match through BaseChest, so one silver row covers every arena.
json stores are gone, they nulled out every data ref on load and wrote the null straight back on save.
shop json and the purchase commands ended up in here too.
new logic-derive Command macro submits each command to inventory, manager decodes by vint type. titan-derive loses tagged enums since nothing uses them now. rest of the diff is rustfmt.
