Function settles_a_compaction 

fn settles_a_compaction(update: &SessionUpdate) -> bool

Whether this update reports a compaction’s own outcome, which is the frame that ends one.

The compaction’s result field rather than the null status that rides beside it. The CLI reports a permission-mode change on that same status/null shape, and a bare null read as a settle would fire the post-compaction ask - past both bounds - on a mode toggle, mid-compaction, and spend the ask the settle itself is owed.

A settle with no result field would leave the post-compaction ask unfired and a reading past the token gate unable to be lowered, which is the state this bypass exists to close; the field is on the settle in both pinned captures and a fresh one is where a change to that would show.

The null half is traded for that, and both directions are disclosed: a result present but null would be read as no settle, and the reading would stand until the next compaction. No captured frame carries it - the corpus has exactly three status shapes, a compacting string twice and one settle with a string result - and the null is admitted nowhere else in this predicate.