Got Avalonia.Ui working.

Gamenight.Ui/Gamenight.Ui.Desktop/Gamenight.Ui.Desktop.csproj

@@ -21,6 +21,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\gamenight.ui\gamenight.ui.csproj" />
+    <ProjectReference Include="..\Gamenight.Ui\Gamenight.Ui.csproj" />
   </ItemGroup>
 </Project>

Gamenight.Ui/Gamenight.Ui.Desktop/Program.cs

@@ -1,7 +1,8 @@
 using System;
 using Avalonia;
+using Avalonia.ReactiveUI;
 
-namespace gamenight.ui.Desktop;
+namespace Gamenight.Ui.Desktop;
 
 sealed class Program
 {
@@ -17,5 +18,6 @@ sealed class Program
         => AppBuilder.Configure<App>()
             .UsePlatformDetect()
             .WithInterFont()
-            .LogToTrace();
+            .LogToTrace()
+            .UseReactiveUI();
 }

Gamenight.Ui/Gamenight.Ui.Desktop/app.manifest

@@ -3,7 +3,7 @@
   <!-- This manifest is used on Windows only.
        Don't remove it as it might cause problems with window transparency and embedded controls.
        For more details visit https://learn.microsoft.com/en-us/windows/win32/sbscs/application-manifests -->
-  <assemblyIdentity version="1.0.0.0" name="gamenight.ui.Desktop"/>
+  <assemblyIdentity version="1.0.0.0" name="Gamenight.Ui.Desktop"/>
 
   <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
     <application>