Add XML documentation across gateway, worker, and .NET client

clients/dotnet/MxGateway.Client/MxGatewayClientRetryOptions.cs

@@ -1,15 +1,21 @@
 namespace MxGateway.Client;
 
+/// <summary>Configuration for automatic retry behavior on transient gRPC call failures.</summary>
 public sealed class MxGatewayClientRetryOptions
 {
+    /// <summary>Gets the maximum number of attempts (initial + retries); default is 2.</summary>
     public int MaxAttempts { get; init; } = 2;
 
+    /// <summary>Gets the initial delay between retry attempts; default is 200 milliseconds.</summary>
     public TimeSpan Delay { get; init; } = TimeSpan.FromMilliseconds(200);
 
+    /// <summary>Gets the maximum delay between retry attempts; default is 2 seconds.</summary>
     public TimeSpan MaxDelay { get; init; } = TimeSpan.FromSeconds(2);
 
+    /// <summary>Gets a value indicating whether to add randomness to retry delays; default is true.</summary>
     public bool UseJitter { get; init; } = true;
 
+    /// <summary>Validates the retry options and throws if any constraint is violated.</summary>
     public void Validate()
     {
         if (MaxAttempts <= 0)