feat(gateway): normalize array AddItem suffix and expand sparse writes at the worker boundary

src/ZB.MOM.WW.MxGateway.Server/Sessions/SessionManager.cs

@@ -29,6 +29,7 @@ public sealed class SessionManager : ISessionManager
     private readonly Grpc.MxAccessGrpcMapper _eventMapper;
     private readonly ILogger<SessionEventDistributor> _distributorLogger;
     private readonly Dashboard.Hubs.IDashboardEventBroadcaster? _dashboardEventBroadcaster;
+    private readonly ArrayAddressNormalizer? _addressNormalizer;
 
     /// <summary>
     /// Initializes a new instance of <see cref="SessionManager"/>.
@@ -47,6 +48,11 @@ public sealed class SessionManager : ISessionManager
     ///     dashboard receives events regardless of whether a gRPC client is streaming. Null in
     ///     unit tests that do not exercise the dashboard mirror.
     /// </param>
+    /// <param name="addressNormalizer">
+    ///     Rewrites bare array AddItem addresses to their writable <c>[]</c> form using Galaxy
+    ///     metadata; handed to each session so the normalization runs at the outbound choke point.
+    ///     Null in unit tests that do not exercise array-write ergonomics.
+    /// </param>
     public SessionManager(
         ISessionRegistry registry,
         ISessionWorkerClientFactory workerClientFactory,
@@ -56,7 +62,8 @@ public sealed class SessionManager : ISessionManager
         ILogger<SessionManager>? logger = null,
         Grpc.MxAccessGrpcMapper? eventMapper = null,
         ILogger<SessionEventDistributor>? distributorLogger = null,
-        Dashboard.Hubs.IDashboardEventBroadcaster? dashboardEventBroadcaster = null)
+        Dashboard.Hubs.IDashboardEventBroadcaster? dashboardEventBroadcaster = null,
+        ArrayAddressNormalizer? addressNormalizer = null)
     {
         _registry = registry ?? throw new ArgumentNullException(nameof(registry));
         _workerClientFactory = workerClientFactory ?? throw new ArgumentNullException(nameof(workerClientFactory));
@@ -67,6 +74,7 @@ public sealed class SessionManager : ISessionManager
         _eventMapper = eventMapper ?? new Grpc.MxAccessGrpcMapper();
         _distributorLogger = distributorLogger ?? NullLogger<SessionEventDistributor>.Instance;
         _dashboardEventBroadcaster = dashboardEventBroadcaster;
+        _addressNormalizer = addressNormalizer;
         _options = options.Value;
         _sessionSlots = new SemaphoreSlim(_options.Sessions.MaxSessions, _options.Sessions.MaxSessions);
     }
@@ -506,7 +514,8 @@ public sealed class SessionManager : ISessionManager
             openedAt,
             eventStreaming,
             TimeSpan.FromSeconds(Math.Max(0, _options.Sessions.DetachGraceSeconds)),
-            TimeSpan.FromMilliseconds(Math.Max(0, _options.Sessions.WorkerReadyWaitTimeoutMs)));
+            TimeSpan.FromMilliseconds(Math.Max(0, _options.Sessions.WorkerReadyWaitTimeoutMs)),
+            _addressNormalizer);
     }
 
     private static string CreateClientCorrelationId(