fix: Component.onCompleted doesn't work on QML Singletons

Replaced with Timer { interval: 0; running: true } in:
- Session.qml (boot IPC audit)
- SessionAudit.qml (init log)
- SessionEvents.qml (init log)

surfaces/quickshell/modules/common/functions/Session.qml

@@ -424,8 +424,16 @@ Singleton {
     // If a new IpcHandler is added, this comment must be updated. The
     // console.log below is the runtime check; the comment is the human
     // audit trail.
-    Component.onCompleted: {
-        console.log("[session] boot IPC audit — shell exposes: "
-            + "lock, lock2, dock, sidebar, session, overview, keyboard, appInventory");
+    // NOTE: Component.onCompleted doesn't work on Singletons in QML,
+    // so the audit log fires via a zero-delay Timer instead.
+    Timer {
+        id: bootAuditTimer
+        interval: 0
+        repeat: false
+        running: true
+        onTriggered: {
+            console.log("[session] boot IPC audit — shell exposes: "
+                + "lock, lock2, dock, sidebar, session, overview, keyboard, appInventory");
+        }
     }
 }

surfaces/quickshell/services/SessionAudit.qml

@@ -214,7 +214,11 @@ Singleton {
         }
     }
 
-    Component.onCompleted: {
-        console.log("[audit] initialized; log at " + root.auditPath);
+    Timer {
+        id: initLogTimer
+        interval: 0
+        repeat: false
+        running: true
+        onTriggered: console.log("[audit] initialized; log at " + root.auditPath)
     }
 }

surfaces/quickshell/services/SessionEvents.qml

@@ -320,8 +320,12 @@ Singleton {
         }
     }
 
-    Component.onCompleted: {
-        console.log("[session-events] initialized; sleep inhibitor held="
-            + root.sleepInhibitorHeld);
+    Timer {
+        id: initLogTimer
+        interval: 0
+        repeat: false
+        running: true
+        onTriggered: console.log("[session-events] initialized; sleep inhibitor held="
+            + root.sleepInhibitorHeld)
     }
 }