Panel: pulsing dot on Update when a new server version is available

The dot replaces the small 'new' badge; the first update check now starts as
soon as the panel asks for the update status instead of 60 s after start.

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

Updater.cs

@@ -132,8 +132,16 @@ public sealed class Updater
         });
     }
 
+    bool firstCheckStarted;
+
     public object Status()
     {
+        // Noch nie geprüft (gerade erst gestartet): jetzt im Hintergrund prüfen, damit das Panel den Punkt bald zeigt
+        if (lastCheckUtc == null && !firstCheckStarted)
+        {
+            firstCheckStarted = true;
+            _ = Task.Run(async () => { try { await CheckAsync(); } catch { } });
+        }
         lock (gate)
         {
             var sdkInfo = sdk;