feat(modules): pause background threads when display is asleep

Currently, modules polling hardware nodes continuously wake up kernel drivers even when the monitor is asleep (e.g., DPMS off), flooding dmesg.

- Adds 'disable-on-sleep' config flag
- Hooks GTK window map/unmap signals to track DPMS state
- Propagates suspend/resume calls to AModule worker threads

include/bar.hpp

@@ -75,6 +75,8 @@ class Bar : public sigc::trackable {
   util::KillSignalAction getOnSigusr1Action();
   util::KillSignalAction getOnSigusr2Action();
 
+  void toggleSuspend(bool suspend);
+
   struct waybar_output* output;
   Json::Value config;
   struct wl_surface* surface;