feat(worker): implement 6 MXAccess COM commands in executor

Wire up the previously-unimplemented Suspend, Activate, AuthenticateUser,
ArchestrAUserToId, AddBufferedItem, and SetBufferedUpdateInterval command
kinds in MxAccessCommandExecutor. These are real COM calls and run on the
STA via the executor.

- IMxAccessServer gains the 6 methods; MxAccessComServer routes them to the
  right interface version (Suspend/Activate -> ILMXProxyServer4 out MxStatus,
  AuthenticateUser -> base ILMXProxyServer, ArchestrAUserToId ->
  ILMXProxyServer2, AddBufferedItem/SetBufferedUpdateInterval ->
  ILMXProxyServer5).
- Suspend/Activate surface the native MxStatus, converted to MxStatusProxy
  via the existing MxStatusProxyConverter.
- AuthenticateUser hands the credential straight to MXAccess and never logs
  it; native HResult failures propagate via the dispatcher.
- MxAccessSession gains matching pass-throughs; AddBufferedItem registers
  the item handle in the handle registry.
- Unit tests (fake IMxAccessServer / fake COM object) cover each arm plus a
  password-non-leak assertion; existing IMxAccessServer fakes updated.

No proto changes (all request/reply messages already exist).

src/ZB.MOM.WW.MxGateway.Worker/MxAccess/MxAccessComServer.cs

@@ -140,6 +140,89 @@ public sealed class MxAccessComServer : IMxAccessServer
         AsProxyServer4().AdviseSupervisory(serverHandle, itemHandle);
     }
 
+    /// <inheritdoc />
+    public object Suspend(
+        int serverHandle,
+        int itemHandle)
+    {
+        if (mxAccessComObject is IMxAccessServer typedFake)
+        {
+            return typedFake.Suspend(serverHandle, itemHandle);
+        }
+
+        AsProxyServer4().Suspend(serverHandle, itemHandle, out MxStatus status);
+        return status;
+    }
+
+    /// <inheritdoc />
+    public object Activate(
+        int serverHandle,
+        int itemHandle)
+    {
+        if (mxAccessComObject is IMxAccessServer typedFake)
+        {
+            return typedFake.Activate(serverHandle, itemHandle);
+        }
+
+        AsProxyServer4().Activate(serverHandle, itemHandle, out MxStatus status);
+        return status;
+    }
+
+    /// <inheritdoc />
+    public int AuthenticateUser(
+        int serverHandle,
+        string verifyUser,
+        string verifyUserPassword)
+    {
+        if (mxAccessComObject is IMxAccessServer typedFake)
+        {
+            return typedFake.AuthenticateUser(serverHandle, verifyUser, verifyUserPassword);
+        }
+
+        return AsProxyServer().AuthenticateUser(serverHandle, verifyUser, verifyUserPassword);
+    }
+
+    /// <inheritdoc />
+    public int ArchestrAUserToId(
+        int serverHandle,
+        string userIdGuid)
+    {
+        if (mxAccessComObject is IMxAccessServer typedFake)
+        {
+            return typedFake.ArchestrAUserToId(serverHandle, userIdGuid);
+        }
+
+        return AsProxyServer2().ArchestrAUserToId(serverHandle, userIdGuid);
+    }
+
+    /// <inheritdoc />
+    public int AddBufferedItem(
+        int serverHandle,
+        string itemDefinition,
+        string itemContext)
+    {
+        if (mxAccessComObject is IMxAccessServer typedFake)
+        {
+            return typedFake.AddBufferedItem(serverHandle, itemDefinition, itemContext);
+        }
+
+        return AsProxyServer5().AddBufferedItem(serverHandle, itemDefinition, itemContext);
+    }
+
+    /// <inheritdoc />
+    public void SetBufferedUpdateInterval(
+        int serverHandle,
+        int updateIntervalMilliseconds)
+    {
+        if (mxAccessComObject is IMxAccessServer typedFake)
+        {
+            typedFake.SetBufferedUpdateInterval(serverHandle, updateIntervalMilliseconds);
+            return;
+        }
+
+        AsProxyServer5().SetBufferedUpdateInterval(serverHandle, updateIntervalMilliseconds);
+    }
+
     /// <inheritdoc />
     public void Write(
         int serverHandle,
@@ -216,6 +299,14 @@ public sealed class MxAccessComServer : IMxAccessServer
                 + $"{nameof(ILMXProxyServer)} or {nameof(IMxAccessServer)}.");
     }
 
+    private ILMXProxyServer2 AsProxyServer2()
+    {
+        return mxAccessComObject as ILMXProxyServer2
+            ?? throw new InvalidOperationException(
+                $"MXAccess COM object of type '{mxAccessComObject.GetType().FullName}' does not implement "
+                + $"{nameof(ILMXProxyServer2)} or {nameof(IMxAccessServer)}.");
+    }
+
     private ILMXProxyServer3 AsProxyServer3()
     {
         return mxAccessComObject as ILMXProxyServer3
@@ -231,4 +322,12 @@ public sealed class MxAccessComServer : IMxAccessServer
                 $"MXAccess COM object of type '{mxAccessComObject.GetType().FullName}' does not implement "
                 + $"{nameof(ILMXProxyServer4)} or {nameof(IMxAccessServer)}.");
     }
+
+    private ILMXProxyServer5 AsProxyServer5()
+    {
+        return mxAccessComObject as ILMXProxyServer5
+            ?? throw new InvalidOperationException(
+                $"MXAccess COM object of type '{mxAccessComObject.GetType().FullName}' does not implement "
+                + $"{nameof(ILMXProxyServer5)} or {nameof(IMxAccessServer)}.");
+    }
 }