Git works through ssh. So you need the same system as sshing into your machine. You just make a user group git and then let git and ssh handle things. And if you don’t need people to push to your repo, then it’s a lot easier as it’s now similar to hosting a website/file server.

Wait poppler-utils can do a lot of pdf related things. Haven’t tried rearranging but it has tools for separating pages and uniting them. And pandoc can covert between a lot of document formats. But it doesn’t do it from pdf, can use pdftext, inkscape, graphicsmagick etc based on what you want to extract (text, vector graphics, raster graphics) etc.

Didn’t even know about the org, but that’s the QR scanner I have been using.

Many people accept ad, or online website to do simple things like QR code, file conversion etc way too easily.