Add Remote Desktop (JPEG-over-WebSocket), Agent v2.2.0

- RtcService.cs: Screen capture via Graphics.CopyFromScreen, ~8fps JPEG stream over WebSocket
- shellServer.js: Separate rdp-agent/rdp types with independent socket maps (no shell collision)
- AgentDetailPage: WebSocket-based RemoteDesktop component replaces WebRTC attempt
- setup.iss: Fixed filename to include 'v' prefix (IT-Nexus-Agent-Setup-v2.2.0.exe)
- Removed SIPSorcery dependencies, added System.Drawing.Common

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

agent-cs/AgentWorker.cs

@@ -6,7 +6,7 @@ namespace ITNexusAgent;
 
 public class AgentWorker
 {
-    private const string Version = "2.1.2";
+    private const string Version = "2.2.0";
     private const string DataDir = @"C:\ProgramData\IT Nexus Agent";
     private const string ConfigPath = @"C:\ProgramData\IT Nexus Agent\config.json";
     private const string StatusPath = @"C:\ProgramData\IT Nexus Agent\status.json";
@@ -43,6 +43,10 @@ public class AgentWorker
         var shellService = new ShellService(_config.ServerUrl, _config.AgentKey, SystemInfoService.GetHostname());
         _ = shellService.RunAsync(_ct);
 
+        // WebRTC Remote Desktop Service im Hintergrund starten
+        var rtcService = new RtcService(_config.ServerUrl, _config.AgentKey, SystemInfoService.GetHostname());
+        _ = rtcService.RunAsync(_ct);
+
         while (!_ct.IsCancellationRequested)
         {
             await RunCycleAsync();