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

src/MxGateway.Tests/Security/Authentication/SqliteAuthStoreTests.cs

@@ -8,8 +8,14 @@ using MxGateway.Server.Security.Authentication;
 
 namespace MxGateway.Tests.Security.Authentication;
 
+/// <summary>
+/// Tests for <see cref="SqliteAuthStore"/>.
+/// </summary>
 public sealed class SqliteAuthStoreTests
 {
+    /// <summary>
+    /// Verifies that MigrateAsync initializes the database schema.
+    /// </summary>
     [Fact]
     public async Task MigrateAsync_EmptyDatabase_InitializesCurrentSchema()
     {
@@ -25,6 +31,9 @@ public sealed class SqliteAuthStoreTests
         Assert.True(await TableExistsAsync(databasePath, SqliteAuthSchema.ApiKeyAuditTable));
     }
 
+    /// <summary>
+    /// Verifies that MigrateAsync migrates and is idempotent.
+    /// </summary>
     [Fact]
     public async Task MigrateAsync_ExistingVersionZeroDatabase_MigratesIdempotently()
     {
@@ -42,6 +51,9 @@ public sealed class SqliteAuthStoreTests
         Assert.True(await TableExistsAsync(databasePath, SqliteAuthSchema.ApiKeyAuditTable));
     }
 
+    /// <summary>
+    /// Verifies that gateway startup fails with a newer schema version.
+    /// </summary>
     [Fact]
     public async Task StartAsync_NewerSchemaVersion_BlocksStartup()
     {
@@ -60,6 +72,9 @@ public sealed class SqliteAuthStoreTests
         Assert.Contains("newer than supported version", exception.Message, StringComparison.Ordinal);
     }
 
+    /// <summary>
+    /// Verifies that FindActiveByKeyIdAsync returns an active key.
+    /// </summary>
     [Fact]
     public async Task FindActiveByKeyIdAsync_ExistingActiveKey_ReturnsKey()
     {
@@ -80,6 +95,9 @@ public sealed class SqliteAuthStoreTests
         Assert.Null(key.RevokedUtc);
     }
 
+    /// <summary>
+    /// Verifies that FindActiveByKeyIdAsync returns null for a revoked key.
+    /// </summary>
     [Fact]
     public async Task FindActiveByKeyIdAsync_RevokedKey_ReturnsNull()
     {
@@ -100,6 +118,9 @@ public sealed class SqliteAuthStoreTests
         Assert.NotNull(storedKey.RevokedUtc);
     }
 
+    /// <summary>
+    /// Verifies that the audit store persists audit events.
+    /// </summary>
     [Fact]
     public async Task ApiKeyAuditStore_AppendAsync_PersistsAuditEvent()
     {