🌐 Update German translations for recently updated docs (using LLMs)

This is done with the German LLM prompt file (#13931), if there are things that are wrong in this PR, things that shouldn't be updated or things missing, it would be better to tweak that prompt file to instruct the LLM to better handle those cases than to review this PR directly.

These are the existing translations that have been updated in the original files in English since the last update in German.

These are probably the most delicate, because the prompt is adjusted to try both:

• Update the existing translation to cover whatever is new in the original docs in English.
• Keep what's already fine, avoid just rewriting everything every time, otherwise this could run over and over again generating something completely new each time, and any update would make the diff giant, instead of focusing on what actually changed.

Both objectives are at odds, one would expect the LLM to change more things, the other would expect the LLM to change fewer things.

There are some pages that have changed quite a bit in the original in English since they were translated, so I imagine there's a chance the LLM would end up defaulting to changing more in those files.

There are also some files that have changed only in specific sections, for example adding or removing things at the end. It seems the LLM can get these fairly well, only adding (or removing) that final section but respecting the rest.

If there are some files that are changed too much unnecessarily, or not working well, maybe a note with which files are okay to merge would work, so that I can remove the bad ones to tweak them further and keep the good translation files.