If the current desktop environment is sway, the smartpause plugin will
spawn a swayidle process that outputs the current time on idle and
resume. Using that info, we can determine:
1. Whether the system is currently idle (idle timestamp > active timestamp)
2. How many seconds the system has been idle (current timestamp - idle timestamp)
Since swayidle uses the KDE idle protocol, it might be possible to
extend this to Wayland KDE as well.
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