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

src/MxGateway.Server/Security/Authorization/GatewayRequestIdentityAccessor.cs

@@ -6,8 +6,12 @@ public sealed class GatewayRequestIdentityAccessor : IGatewayRequestIdentityAcce
 {
     private readonly AsyncLocal<ApiKeyIdentity?> currentIdentity = new();
 
+    /// <summary>Gets the current request identity.</summary>
     public ApiKeyIdentity? Current => currentIdentity.Value;
 
+    /// <summary>Sets the current identity and returns a scope that restores the previous identity.</summary>
+    /// <param name="identity">The identity to push.</param>
+    /// <returns>Disposable scope.</returns>
     public IDisposable Push(ApiKeyIdentity identity)
     {
         ArgumentNullException.ThrowIfNull(identity);
@@ -24,6 +28,7 @@ public sealed class GatewayRequestIdentityAccessor : IGatewayRequestIdentityAcce
     {
         private bool disposed;
 
+        /// <summary>Restores the previous identity.</summary>
         public void Dispose()
         {
             if (disposed)