Scene 4b: fetch what scene 4 ticked into the cache, touching nothing in the
game folder, so the questions come after the transfers. Cancel is the only
button, honoured here because a half-finished download costs nothing; the
page moves on by itself.
The questions come next, without what never arrived; when nothing did, or
the run was cancelled, it ends at the summary, by page id, since nothing
new could honestly be installed. When a category is left with nothing to
pick from, it is back to scene 4 for another selection.
Logs each package that never arrived and unticks it, unless the cache holds
a copy: a failed UPDATE keeps the installed version, which an untick would
have the plan uninstall.