fix(desktop): harden topic ids and tray probing

desktop/tabs.go

@@ -5156,7 +5156,10 @@ func newTabID() string {
 
 func newTopicID() string {
 	var b [8]byte
-	rand.Read(b[:])
+	if _, err := rand.Read(b[:]); err != nil {
+		now := time.Now().UTC()
+		return "topic_" + now.Format("20060102-150405") + "_" + fmt.Sprintf("%09d", now.Nanosecond())
+	}
 	return "topic_" + time.Now().UTC().Format("20060102-150405") + "_" + hex.EncodeToString(b[:])
 }
 

desktop/tray_supported_unix.go

@@ -9,7 +9,8 @@ func traySupported() bool {
 	if err != nil {
 		return false
 	}
-	defer conn.Close()
+	// SessionBus returns a shared singleton connection. Do not close it here:
+	// other desktop integrations in this process may still be using it.
 	obj := conn.Object("org.freedesktop.DBus", "/org/freedesktop/DBus")
 	var owner string
 	return obj.Call("org.freedesktop.DBus.GetNameOwner", 0, "org.kde.StatusNotifierWatcher").Store(&owner) == nil && owner != ""