feat(twincat): 1-D array symbol read via ADS + IsArray discovery

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/ITwinCATClient.cs

@@ -40,11 +40,15 @@ public interface ITwinCATClient : IDisposable
     /// <param name="symbolPath">The ADS symbol path.</param>
     /// <param name="type">The target data type.</param>
     /// <param name="bitIndex">Optional bit index for bit extraction within a word.</param>
+    /// <param name="arrayCount">When non-null, read a 1-D array of this many <paramref name="type"/>
+    ///     elements; the boxed value is the element-typed CLR array (<c>int[]</c> / <c>float[]</c> /
+    ///     <c>bool[]</c> / <c>string[]</c> / …). When null, read a scalar (Phase 4c).</param>
     /// <param name="cancellationToken">Cancellation token for the read operation.</param>
     Task<(object? value, uint status)> ReadValueAsync(
         string symbolPath,
         TwinCATDataType type,
         int? bitIndex,
+        int? arrayCount,
         CancellationToken cancellationToken);
 
     /// <summary>
@@ -113,13 +117,19 @@ public interface ITwinCATNotificationHandle : IDisposable { }
 ///     path + detected <see cref="TwinCATDataType"/> + read-only flag.
 /// </summary>
 /// <param name="InstancePath">Full dotted symbol path (e.g. <c>MAIN.bStart</c>, <c>GVL.Counter</c>).</param>
-/// <param name="DataType">Mapped <see cref="TwinCATDataType"/>; <c>null</c> when the symbol's type
-///     doesn't map onto our supported atomic surface (UDTs, pointers, function blocks).</param>
+/// <param name="DataType">Mapped <see cref="TwinCATDataType"/> of the (element) type; <c>null</c>
+///     when the symbol's type doesn't map onto our supported atomic surface (UDTs, pointers,
+///     function blocks). For an array symbol this is the ELEMENT type, with <paramref name="ArrayLength"/>
+///     carrying the dimension.</param>
 /// <param name="ReadOnly"><c>true</c> when the symbol's AccessRights flag forbids writes.</param>
+/// <param name="ArrayLength">When non-null, the symbol is a 1-D array of this many
+///     <paramref name="DataType"/> elements. <c>null</c> = scalar. Multi-dimensional arrays are
+///     reported as <c>null</c> (treated as scalar/unsupported) — only 1-D is in scope for Phase 4c.</param>
 public sealed record TwinCATDiscoveredSymbol(
     string InstancePath,
     TwinCATDataType? DataType,
-    bool ReadOnly);
+    bool ReadOnly,
+    int? ArrayLength = null);
 
 /// <summary>Factory for <see cref="ITwinCATClient"/>s. One client per device.</summary>
 public interface ITwinCATClientFactory