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

src/MxGateway.Server/Security/Authentication/SqliteApiKeyAdminStore.cs

@@ -2,8 +2,12 @@ using Microsoft.Data.Sqlite;
 
 namespace MxGateway.Server.Security.Authentication;
 
+/// <summary>
+/// SQLite-backed storage for API key administration (create, list, revoke, rotate).
+/// </summary>
 public sealed class SqliteApiKeyAdminStore(AuthSqliteConnectionFactory connectionFactory) : IApiKeyAdminStore
 {
+    /// <inheritdoc />
     public async Task CreateAsync(ApiKeyCreateRequest request, CancellationToken cancellationToken)
     {
         await using SqliteConnection connection = connectionFactory.CreateConnection();
@@ -35,6 +39,7 @@ public sealed class SqliteApiKeyAdminStore(AuthSqliteConnectionFactory connectio
         await command.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(false);
     }
 
+    /// <inheritdoc />
     public async Task<IReadOnlyList<ApiKeyRecord>> ListAsync(CancellationToken cancellationToken)
     {
         await using SqliteConnection connection = connectionFactory.CreateConnection();
@@ -60,6 +65,7 @@ public sealed class SqliteApiKeyAdminStore(AuthSqliteConnectionFactory connectio
         return records;
     }
 
+    /// <inheritdoc />
     public async Task<bool> RevokeAsync(string keyId, DateTimeOffset revokedUtc, CancellationToken cancellationToken)
     {
         await using SqliteConnection connection = connectionFactory.CreateConnection();
@@ -79,6 +85,7 @@ public sealed class SqliteApiKeyAdminStore(AuthSqliteConnectionFactory connectio
         return rows > 0;
     }
 
+    /// <inheritdoc />
     public async Task<bool> RotateAsync(
         string keyId,
         byte[] secretHash,