Fix: Remote Desktop — 60fps, Screen-Wechsel live, Consent-Dialog sichtbar (v2.3.0)

- CaptureModeRunner: Thread.Sleep(150) → 16ms (~60fps) + Skip-if-unchanged via Pixel-Hash
- RtcService: rdp_switch_screen Handler — Screen wechseln ohne Consent-Dialog
- RtcService: Fallback bei Consent-Fehler → rdp_denied statt silent capture
- RdpConsentWindow: WindowStyle=ToolWindow + ShowInTaskbar=True (jetzt in Taskleiste sichtbar)
- RemoteDesktopPanel: Screen-Dropdown auch während aktiver Verbindung nutzbar
- Version: 2.2.0 → 2.3.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

agent-cs/Services/RtcService.cs

@@ -70,6 +70,15 @@ public class RtcService
                 _ = ConsentAndCaptureAsync(ws, screenIdx, captureCts.Token);
                 AgentWorker.Log($"RDP: Consent angefordert (screen={screenIdx})");
             }
+            else if (type == "rdp_switch_screen" && captureCts != null)
+            {
+                // Consent bereits erteilt — nur Screen wechseln, kein erneuter Dialog
+                var newScreen = obj["screen"]?.ToObject<int>() ?? 0;
+                captureCts.Cancel();
+                captureCts = CancellationTokenSource.CreateLinkedTokenSource(ct);
+                _ = CapturePipeLoopAsync(ws, newScreen, captureCts.Token);
+                AgentWorker.Log($"RDP: Screen gewechselt zu {newScreen}");
+            }
             else if (type == "rdp_stop" && captureCts != null)
             {
                 captureCts.Cancel();
@@ -93,8 +102,10 @@ public class RtcService
         if (!SpawnConsentHelper(exePath, consentPort.ToString()))
         {
             consentListener.Stop();
-            AgentWorker.Log("RDP: Consent-Helper fehlgeschlagen, starte ohne Consent");
-            await CapturePipeLoopAsync(ws, screenIdx, ct);
+            AgentWorker.Log("RDP: Consent-Helper fehlgeschlagen, verweigere Zugriff");
+            var failed = Encoding.UTF8.GetBytes("{\"type\":\"rdp_denied\",\"reason\":\"consent_spawn_failed\"}");
+            if (ws.State == WebSocketState.Open)
+                await ws.SendAsync(new ArraySegment<byte>(failed), WebSocketMessageType.Text, true, CancellationToken.None);
             return;
         }
 

agent-cs/Services/ShellService.cs

@@ -40,7 +40,7 @@ public class ShellService
             + $"/ws?type=agent&key={Uri.EscapeDataString(_agentKey)}&hostname={Uri.EscapeDataString(_hostname)}";
 
         using var ws = new ClientWebSocket();
-        ws.Options.SetRequestHeader("User-Agent", "IT-Nexus-Agent/2.1.2");
+        ws.Options.SetRequestHeader("User-Agent", "IT-Nexus-Agent/2.3.0");
 
         await ws.ConnectAsync(new Uri(wsUrl), ct);
         AgentWorker.Log("SHELL: WebSocket verbunden");