logger: add a dedicated QML logging Singleton

- adds log.info/error/debug/warn/fatal
- adds ability to write logs to any file
- add CLI options in addition to env to set log levels

quickshell/Modules/Lock/LockScreenDemo.qml

@@ -3,9 +3,11 @@ pragma ComponentBehavior: Bound
 import QtQuick
 import Quickshell
 import Quickshell.Wayland
+import qs.Services
 
 PanelWindow {
     id: root
+    readonly property var log: Log.scoped("LockScreenDemo")
 
     property bool demoActive: false
 
@@ -25,12 +27,12 @@ PanelWindow {
     color: "transparent"
 
     function showDemo(): void {
-        console.log("Showing lock screen demo");
+        log.debug("Showing lock screen demo");
         demoActive = true;
     }
 
     function hideDemo(): void {
-        console.log("Hiding lock screen demo");
+        log.debug("Hiding lock screen demo");
         demoActive = false;
     }