New Feature: Runtime configuration/API

Is your feature request related to a problem? If so, please describe the problem.
There currently is no way to modify settings runtime. You need to kill the application, edit the config file and then launch again. I personally would like to integrate it with my smarthome (example: 10% brightness when watching a movie, 100% brightness when running a game). I don't know if it is only me, but right now it doesn't even accept ctrl-c to exit from the command line...

Describe the feature / solution to your problem you'd like
It would be a dream if we could have a very simple Web API integrated with simple functions for changing brightness/themes. Maybe a Display on/off it it is physically possible.

Describe alternatives you've considered / and or tested
I haven't tested it yet, but the alternative would probably be keeping seperate directories with different config files and killing/starting the processes as required. I currently do this to control some other programs that don't support any kind of remote control (like the hue sync app) - but it is a real pain...

Environment:

• I am on Windows, but that shouldn't matter...

No files, tests, or entry points are named in the issue. Begin by locating how configuration is loaded and how brightness, themes, display power, and command-line shutdown are handled. Define the runtime API scope and completion criteria before implementing anything.