I’m not sure about the “audiobooks” part but you can use your browser from android to connect to calibre https://manual.calibre-ebook.com/faq.html#over-the-air

BTW I used for many years Moon+ Reader to read aloud my ebook on android. Not quite as a real audiobook but good enough https://play.google.com/store/apps/details?id=com.flyersoft.moonreader

If you are able to see every recipe I’d rule out data corruption. If the issue arise only when try to create a new recipe (or editing an old one) the usual thing to check are permissions. Don’t zip but use some tools to maintain permissions (tar, rsync, etc) and try again

If you want a way to self host git (not github) repositories you can check this list https://www.slant.co/topics/1440/~best-self-hosted-web-based-git-repository-managers

https://smarthomescene.com/reviews/aqara-fp2-human-presence-sensor-review/

UPDATE 24.04.2023: Aqara has released a new firmware update 1.1.6_0005.0025 which enables local control. The FP2 can now be used without an internet connection, hub, or app dependence in Home Assistant after it’s initial setup.

So, yes, after the initial setup (you may need an internet connection to download and install the newer firmware) no internet connection is needed at all.