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

src/MxGateway.Tests/Gateway/Dashboard/DashboardAuthenticatorTests.cs

@@ -7,8 +7,14 @@ using MxGateway.Server.Security.Authorization;
 
 namespace MxGateway.Tests.Gateway.Dashboard;
 
+/// <summary>
+/// Tests for dashboard authentication using API keys.
+/// </summary>
 public sealed class DashboardAuthenticatorTests
 {
+    /// <summary>
+    /// Verifies an admin-scoped key produces a valid cookie principal.
+    /// </summary>
     [Fact]
     public async Task AuthenticateAsync_AdminKey_ReturnsCookiePrincipal()
     {
@@ -29,6 +35,9 @@ public sealed class DashboardAuthenticatorTests
         Assert.Equal("Bearer mxgw_operator01_super-secret", verifier.LastAuthorizationHeader);
     }
 
+    /// <summary>
+    /// Verifies a non-admin key fails authentication without exposing the API key.
+    /// </summary>
     [Fact]
     public async Task AuthenticateAsync_NonAdminKey_ReturnsFailureWithoutRawApiKey()
     {
@@ -44,6 +53,9 @@ public sealed class DashboardAuthenticatorTests
         Assert.DoesNotContain("super-secret", result.FailureMessage, StringComparison.Ordinal);
     }
 
+    /// <summary>
+    /// Verifies that when admin scope is not required, any authenticated key is accepted.
+    /// </summary>
     [Fact]
     public async Task AuthenticateAsync_RequireAdminScopeFalse_AllowsAuthenticatedKey()
     {
@@ -59,6 +71,9 @@ public sealed class DashboardAuthenticatorTests
         Assert.NotNull(result.Principal);
     }
 
+    /// <summary>
+    /// Verifies an invalid key returns a generic failure message.
+    /// </summary>
     [Fact]
     public async Task AuthenticateAsync_InvalidKey_ReturnsGenericFailure()
     {
@@ -97,10 +112,17 @@ public sealed class DashboardAuthenticatorTests
             Scopes: new HashSet<string>(scopes, StringComparer.Ordinal)));
     }
 
+    /// <summary>
+    /// Test implementation that records the authorization header for verification.
+    /// </summary>
     private sealed class FakeApiKeyVerifier(ApiKeyVerificationResult result) : IApiKeyVerifier
     {
+        /// <summary>
+        /// The authorization header that was last verified.
+        /// </summary>
         public string? LastAuthorizationHeader { get; private set; }
 
+        /// <inheritdoc />
         public Task<ApiKeyVerificationResult> VerifyAsync(
             string? authorizationHeader,
             CancellationToken cancellationToken)