Feature Request: Enable admins to create download options based on custom URL scheme

[ethanxrosen]

I think this would open up a lot better usability for people using calibre-web in combination with client apps on their phones or other devices.

This came up for me specifically when attempting to download an audiobook I had stored in calibre-web to a popular iOS app BookPlayer. Currently I need to download the audiobook from calibre using a browser, open up BookPlayer, find the book among the folders on my phone, import the download, and after it is imported a duplicate file remains in my downloads folder, which I should remember to delete lest it takes up storage. This is not so bad but doesn't really pass the "easy for older family members" test.

If, say next to 'send to kindle' there was a custom option I could define named 'Send to BookPlayer' with a URL something like below

bookplayer://download?url="https://direct-download-link-to-your-file-with-http-auth-or-access-token.m4b"

in 1 click the book would load to the app I want. Sure there are other apps that could make use of a similar strategy too!