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/IT-Nexus-Agent.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net8.0-windows</TargetFramework>
+    <TargetFramework>net8.0-windows10.0.17763.0</TargetFramework>
     <UseWPF>true</UseWPF>
     <UseWindowsForms>true</UseWindowsForms>
     <AssemblyName>IT-Nexus-Agent</AssemblyName>
@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Resource Include="icon.ico"/>
+    <Resource Include="icon.ico" />
     <Content Include="icon.ico">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
@@ -28,6 +28,7 @@
 
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageReference Include="System.Drawing.Common" Version="8.0.0" />
     <PackageReference Include="System.Management" Version="8.0.0" />
     <PackageReference Include="System.ServiceProcess.ServiceController" Version="8.0.0" />
   </ItemGroup>