[Enhancement]: Allow separate export folder for metadata embed and m4b creation

[mew1033]

Type of Enhancement

Server Backend

Describe the Feature/Enhancement

I'd like to be able to specify a different folder for the output of the metadata embed and the m4b bundling tools. Another option would be to run the tool, then download the result in the browser.

Why would this be helpful?

I don't want audiobookshelf (or any of my other services) to have write access to my audiobook folders. I mount the audiobook directory as read only. But I still very much appreciate all the metadata/m4b tools that audiobookshelf has, and I'd like to utilize them. It'd be nice if I could specify a different export folder, then download the resulting files and manually replace the files audiobookshelf is looking at.

Future Implementation (Screenshot)

Audiobookshelf Server Version

v2.10.1

[mew1033]

#3182 gets this closer.