Create an exhaustive list of data which is uploaded to iCloud when backup is enabled

[faenil]

Your use case

What would you like to do?

When I created #5498 part of the proposal was related to the creation of a resource that would detail exactly what data the Element iOS client is backing up to iCloud.

Why would you like to do it?

Even after the fix for #5498, the iOS client is still uploading some data to iCloud, even though the iOS team tried do minimize the set of data that is being backed up (see #5558)

Moreover, the discussion at #5498 highlighted that there are some corner cases (new paths/files not being marked as excluded, or bugs/regressions, etc) that might lead to "some" data being uploaded to iCloud, even if for a limited period of time.

How would you like to achieve it?

As agreed with @ara4n #5498 (comment) this could be a section in the README.

My proposal would be to include the following information:

• in the standard scenario, what data is being backed up to iCloud? Which folders/db and what data do they contain, exactly? This would ideally be a list of elements, possibly with pointers to relevant parts of the sourcecode (even just at file/folder level to minimize needed maintenance) so that more experienced users can have an even deeper look, if desired
• what is the exhaustive list of data stored in the folders/dbs which are uploaded to iCloud when no backup prevention is in place? In other words, what is the worst case scenario if things go horribly wrong? :)
  For instance, could unencrypted pictures (or thumbnails) end up on iCloud in case of a bug in the exclusion rules, even when the chat is configured as E2EE?
  Or does Element iOS always store media (pics/videos/etc) on disk in encrypted format and then decrypts it on the fly when they are shown to the user, so that the decrypted data is never saved to disk? (I doubt this is the case, but I hope you get my point :) )
  Different users might have different levels of risks that they are willing to take.
• what are the corner cases (at least those that developers are aware of, as mentioned in What is being backed up to iCloud? #5498) which might lead to some (possibly also stating whcih) data being uploaded to iCloud

Please also have a look at my comment in the other thread, as it provides more examples :)

Have you considered any alternatives?

No response

Additional context

No response