A screen's state: what continuing from the screen needs — the ids its
actions and edges send, a server token that came with the edge's input —
never the user's data, derived from the screen's input and data. A retrace
derives it again from fresh data, so it is not stored: a trail holds none.
A screen's state: what continuing from the screen needs — the ids its actions and edges send, a server token that came with the edge's input — never the user's data, derived from the screen's input and data. A retrace derives it again from fresh data, so it is not stored: a trail holds none.