Rework of the file export (#894)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/wwwroot/changelog/v26.8.2.md

@@ -9,6 +9,8 @@
 - Added speech-to-text for Helmholtz Blablador and GroqCloud, and embeddings for GWDG SAIA. These providers offer these services now, so you can select them when you dictate a message or when you set up a data source.
 - Added embeddings and speech-to-text for Hugging Face, so you can now use it to prepare your own documents for retrieval and to dictate your messages. Hugging Face offers both through a few of its inference providers only, which is why you get a shorter list to choose from there than you do for chatting.
 - Added a model list for Hugging Face. Until now you had to type the name of the model yourself and hope you got it right, down to its capitalization. AI Studio now loads the models your chosen inference provider actually offers, so you pick one from a list and cannot end up with a model that provider does not serve.
+- Added more file formats for exporting an AI answer. The export button used to offer Microsoft Word only; it is now a menu which also writes OpenDocument Text for LibreOffice, LaTeX, Markdown, and a webpage. When an answer contains tables, each of them can be saved on its own as a spreadsheet file, named after the heading above it and ready to open in Excel or LibreOffice Calc. This works in the chat and for the results of every assistant. Many thanks to Nils Kruthoff (`nilskruthoff`) for this contribution.
+- Added a choice of file format to the Batch Processing assistant. When it writes one result file per document, those files were always Markdown; you can now pick Microsoft Word, OpenDocument Text, LaTeX, or a webpage instead. For IT departments: the new setting `DataBatchProcessing.ResultFileFormat` lets you configure the format for your organization.
 - Improved the safety of plugin symbols: AI Studio now shows the symbol of a plugin in isolation, so nothing inside a symbol can reach the rest of the app.
 - Improved how much memory AI Studio needs. Working with large documents used to grow the app to several gigabytes, and on macOS that memory was never handed back. AI Studio now stays at a fraction of that and returns memory to your system. This matters most on devices with little memory, such as a Raspberry Pi.
 - Improved the preview for large documents. It now shows you the beginning of your document instead of loading all of it, so the dialog opens right away. Your complete document still goes to the AI.