Add authentication and improve server side configuration

RemoteExec.Server/Configuration/ExecutionConfiguration.cs

@@ -0,0 +1,14 @@
+namespace RemoteExec.Server.Configuration;
+
+public class ExecutionConfiguration
+{
+    /// <summary>
+    /// Maximum number of concurrent tasks. Default is ProcessorCount * 2.
+    /// </summary>
+    public int? MaxConcurrentTasks { get; set; }
+
+    /// <summary>
+    /// Timeout for assembly loading requests in seconds. Default is 30 seconds.
+    /// </summary>
+    public int AssemblyLoadTimeoutSeconds { get; set; } = 30;
+}