I think so far the best setup Ive seen of this for browser restriction for a session is with running the browser in firejail. https://github.com/netblue30/firejail
Every field of CS has a security aspect to it. Unless you are a legitimate network engineer, learn how to use the network right before learning how to break it.
I'd say start with learning how security works in the world you know. Defensive programming is a very real thing and translates to just about every other field of CS since... Its all running on code. :D
There are quite a few good defensive coding guides out there. Redhat has some really nicely put together guides for you to start learning from.
Remember: Learning how to use a gun and becoming licensed to use the gun isnt gonna teach you nearly as much about security as learning how to build Fort Knox.
Github should natively cook in a project/user based tipping system to help people show their appreciation. This feels lazy to say but I know for a fact I would send tips way more frequently if they made tipping a one click experience.
I know there are third party tools that let projects cook tip functionality into their projects.
With how difficult it is to find time to write open source software alone, time put towards setting that up winds up feeling like me prioritizing thirsting for tips and donations over finishing whatever the original goal of the project was. I know for a fact I'm not the only one who feels that way.
I wrote a python wrapper around sqlite to turn it into a graph database a while back. If you haven't heard of a triplicate store pattern, thats pretty much how you do graphdbs in sql and keep things fast. Here's a link to the project. :)