A rollback button on event E restores the state just after E. So the button on the latest event was a no-op (you're already there), while the scene-start event -- a valid earliest target -- correctly has one. The visible set was effectively shifted one event late. Hide the button on whichever event sits at the current position (the rollback head if set, else the latest checkpoint, now supplied by the backend as state.latest_checkpoint_id since the frontend's own reduce over the async-populated accumulator wasn't reliably reactive). In live play the latest event loses its redundant button; when rolled back, the "you are here" event has none while earlier events show rollback and later ones show redo. Verified in a browser across live, rolled-back, and redo states. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
85 KiB
85 KiB