fix(gui): ensure sessions load on startup and via periodic refresh

- Call ollie.refreshSessions() from Component.onCompleted before
  buildSessionTree() for reliable initial load
- Add a 2-second periodic refresh timer as fallback for missed events

gui/main.qml

@@ -90,6 +90,17 @@ ApplicationWindow {
         onTriggered: chatView.positionViewAtEnd()
     }
 
+    // Periodic session list refresh — fallback for missed events
+    Timer {
+        id: refreshTimer
+        interval: 2000
+        repeat: true
+        running: true
+        onTriggered: {
+            ollie.refreshSessions()
+        }
+    }
+
     // Session ID to kill — set on right-click, consumed by context menu
     property string killTargetSessionId: ""
 
@@ -201,6 +212,8 @@ ApplicationWindow {
             }
         }
         scrollTimer.start()
+        // Ensure we have the latest session list
+        ollie.refreshSessions()
         buildSessionTree()
     }