Fix BeginScope to return proper disposable and AddProvider to throw NotSupportedException

Co-authored-by: MichaelKoster70 <[email protected]>

Author: Copilot

src/Extension/RemoteDebuggerLauncher/Logging/FileLogger.cs

@@ -39,7 +39,7 @@ public FileLogger(string categoryName, string logFilePath, LogLevel minLogLevel)
       /// <inheritdoc />
       public IDisposable BeginScope<TState>(TState state)
       {
-         return null;
+         return NullScope.Instance;
       }
 
       /// <inheritdoc />
@@ -130,5 +130,22 @@ private static string GetLogLevelString(LogLevel logLevel)
                return "UNKN ";
          }
       }
+
+      /// <summary>
+      /// A no-op disposable for scope handling.
+      /// </summary>
+      private sealed class NullScope : IDisposable
+      {
+         public static NullScope Instance { get; } = new NullScope();
+
+         private NullScope()
+         {
+         }
+
+         public void Dispose()
+         {
+            // Do nothing
+         }
+      }
    }
 }

src/Extension/RemoteDebuggerLauncher/Logging/FileLoggerFactory.cs

@@ -50,9 +50,10 @@ public ILogger CreateLogger(string categoryName)
       }
 
       /// <inheritdoc />
+      /// <remarks>This simple implementation does not support adding providers.</remarks>
       public void AddProvider(ILoggerProvider provider)
       {
-         // Not supported for this simple implementation
+         throw new NotSupportedException("This logger factory does not support adding providers.");
       }
 
       /// <inheritdoc />

src/Extension/RemoteDebuggerLauncher/Logging/NullLogger.cs

@@ -23,7 +23,7 @@ internal class NullLogger : ILogger
       /// <inheritdoc />
       public IDisposable BeginScope<TState>(TState state)
       {
-         return null;
+         return NullScope.Instance;
       }
 
       /// <inheritdoc />
@@ -37,5 +37,22 @@ public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Except
       {
          // Do nothing
       }
+
+      /// <summary>
+      /// A no-op disposable for scope handling.
+      /// </summary>
+      private sealed class NullScope : IDisposable
+      {
+         public static NullScope Instance { get; } = new NullScope();
+
+         private NullScope()
+         {
+         }
+
+         public void Dispose()
+         {
+            // Do nothing
+         }
+      }
    }
 }