a panic in a session task now kills that connection, tokio catches it and the
accept loop carries on. with abort it took the whole server down.
the data table RwLock is std so it poisons on panic, and every lookup went
through expect(). one panic would have bricked every later table read, which is
worse than the abort was. it reads the inner value now, the table is read only
once installed.
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.
