I have been using Zotero for a while and syncing my library directory with Syncthing, even though they say not to (no problem in 7 years including PhD and job).
If you want something even more minimalist, it is possible with the command line too, , which is the approximate setup I’m currently using in my pharma job.

Look at the European, having to only stock metric screw sizes, so lucky. Kidding!
I’m definitely going to try this out. Looks great!