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/Services/PolkitService.qml

@@ -6,6 +6,7 @@ import Quickshell
 
 Singleton {
     id: root
+    readonly property var log: Log.scoped("PolkitService")
 
     readonly property bool disablePolkitIntegration: Quickshell.env("DMS_DISABLE_POLKIT") === "1"
 
@@ -17,6 +18,7 @@ Singleton {
             const qmlString = `
                 import QtQuick
                 import Quickshell.Services.Polkit
+import qs.Services
 
                 PolkitAgent {
                 }
@@ -24,10 +26,10 @@ Singleton {
 
             agent = Qt.createQmlObject(qmlString, root, "PolkitService.Agent")
             polkitAvailable = true
-            console.info("PolkitService: Initialized successfully")
+            log.info("Initialized successfully")
         } catch (e) {
             polkitAvailable = false
-            console.warn("PolkitService: Polkit not available - authentication prompts disabled. This requires a newer version of Quickshell.")
+            log.warn("Polkit not available - authentication prompts disabled. This requires a newer version of Quickshell.")
         }
     }