[Feature request]: gracefully disable capture when not wlroots

[Atemu]

Please describe your feature request

wluma currently just crashes when ran with default config in anything other than a wlroots compositor. This is not a sane default.

It should instead automatically disable capture and print a log message at worst.

[max-baz]

Thanks! It sounds good, but there are several things we need to be mindful about.

1. The selling point of the app is screen-contents awareness. I would like people to realize as soon as possible that they can't get what's demonstrated on the gif in README if they don't have the supported setup.
2. Prediction model assumes "stable" setup per output. If user changes between two compositors (say sway and Gnome) and runs wluma on both of them (i.e. screen data is sometimes present), the model data would be corrupted, resulting in unpredictable behavior.

[Atemu]

The selling point of the app is screen-contents awareness. I would like people to realize as soon as possible that they can't get what's demonstrated on the gif in README if they don't have the supported setup.

That's a really good point.

I use wluma primarily for its auto-brightness feature but content-awareness is certainly a selling point and I'd like to at least try it at some point.

Perhaps a more "in your face" warning about the feature being disabled other than a crash would be appropriate; a desktop notification perhaps?

Such a warning should be accompanied by an easy method to disable content-awareness that does not involve having to specify it for each connected monitor. It'd be great if there could be a "I only want auto-brightness" mode.

2. Prediction model assumes "stable" setup per output. If user changes between two compositors (say sway and Gnome) and runs wluma on both of them (i.e. screen data is sometimes present), the model data would be corrupted, resulting in unpredictable behavior.

This smells like a design flaw.

Fixing the design flaw would be the proper solution but still a better fallback could be to reset the model when a different compositor is detected or have separate models for each compositor.