Overhaul post Trixie

This is a great page, but it now needs an overhaul to be correct for Trixie. I am not sure yet how much of the content is only applicable for non-Trixie. Until we have a better handle on how much there is, those exceptional bits should be moved into admonitions (if they're still relevant) or removed.

Once identified If the weight of non-Trixie material is substantial we should move it to sub-pages instead.

These sections on this discussion page can be expanded to track progress. -- jmtd 2025-09-03 09:21:44

Overhaul reflecting default of unshare

The page indicates early on that the situation documented is the "unshare" backend, but that needs to be worked through for the whole page (e.g. there's no clear indication of how to use apt-cacher-ng with unshare). As above, if there is content that is pertinent only to other backends, we should move it into notes and then into sub-pages if there's a lot.

-- jmtd 2025-09-03 09:21:44