feat: RAG zotero pipeline

[cloter]

I would like to pull documents from a local Zotero library for RAG.
Presently we need to include each document manually, it would be really helpful to include a whole tree of documents, either from a directory on the PC or (and this is the feature request) include them from Zotero.
Zotero has an API that could be used for this, see:
https://www.zotero.org/support/dev/client_coding/javascript_api#running_ad_hoc_javascript_in_zotero
I did not look into Open WebUI's code (not being a very experienced programmer) but if somebody has any hints I could try to tackle this.

[tjbck]

https://github.com/urschrei/pyzotero looks promising!