Fix issues found testing stage 5 in a VM

- Calamares branding takes the version from VERSION at ISO build time
- das-update tray hides its icon when updates were installed elsewhere
  (watches the xbps package database)
- Installer removes guest tools of other hypervisors; the live image
  starts VBoxClient only inside VirtualBox
- Live session no longer locks the screen while the installer runs
- das-tools 0.2.0, das-installer 0.2.0, das-settings 0.4.0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

srcpkgs/das-tools/files/src/cmd/das-update/tray.go

@@ -22,6 +22,9 @@ const (
 	firstCheck    = 2 * time.Minute
 	checkInterval = 6 * time.Hour
 	checkTimeout  = 5 * time.Minute
+	// How often to look for updates installed outside the tray: from a
+	// separately started window, das-update --cli or xbps-install.
+	pkgdbInterval = time.Minute
 )
 
 type trayApp struct {
@@ -29,6 +32,7 @@ type trayApp struct {
 	checking bool
 	notified []string // the updates the last notification was about
 	window   *exec.Cmd
+	pkgdb    time.Time // package database time at the last check
 }
 
 func runTray() int {
@@ -69,6 +73,12 @@ func runTray() int {
 		})
 		return false
 	})
+	glib.TimeoutSecondsAdd(uint(pkgdbInterval.Seconds()), func() bool {
+		if t.notified != nil && !xbps.PkgdbTime().Equal(t.pkgdb) {
+			t.check()
+		}
+		return true
+	})
 	gtk.Main()
 	return 0
 }
@@ -78,6 +88,7 @@ func (t *trayApp) check() {
 		return
 	}
 	t.checking = true
+	t.pkgdb = xbps.PkgdbTime()
 	go func() {
 		ctx, cancel := context.WithTimeout(context.Background(), checkTimeout)
 		defer cancel()