TypedStateToken
type TypedStateToken<T> = intersectionState token that carries the value type T.
Created by flareState and passed to ctx.require(), ctx.get(),
and ctx.set(). The token is a plain object: its reference identity is
what makes it unique. Tokens cannot be extended; use flareState to
create a new one.
Assignable to StateToken wherever the value type is not needed.
The _type field is a phantom type: it exists only at compile time to carry
T through the token so state reads and writes stay typed.
Learn: Reading state