Security: admin rights only for Steam-verified SteamIDs; protocol test suite (Tests/)

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

MSCO.Server.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
@@ -15,4 +15,10 @@
     <ApplicationIcon>logo.ico</ApplicationIcon>
   </PropertyGroup>
 
+  <ItemGroup>
+    <!-- Tests sind ein eigenes Projekt im Ordner Tests -->
+    <Compile Remove="Tests/**" />
+    <None Remove="Tests/**" />
+  </ItemGroup>
+
 </Project>