Auto: twincat-1.4 — whole-array reads

Surface int[]? ArrayDimensions on TwinCATTagDefinition + thread it through
ITwinCATClient.ReadValueAsync / WriteValueAsync. When non-null + non-empty,
AdsTwinCATClient issues a single ADS read against the symbol with
clrType.MakeArrayType() and returns the flat 1-D CLR Array; for IEC TIME /
DATE / DT / TOD element types we project per-element to the native
TimeSpan / DateTime so consumers see consistent types regardless of rank.

DiscoverAsync surfaces IsArray=true + ArrayDim=product(dims) onto
DriverAttributeInfo via a new ResolveArrayShape helper. Multi-dim shapes
flatten to the product on the wire — DriverAttributeInfo.ArrayDim is
single-uint today and the OPC UA layer reflects rank via its own metadata.

Native ADS notification subscriptions skip whole-array tags so the OPC UA
layer falls through to a polled snapshot — the per-element AdsNotificationEx
callback shape doesn't fit a flat array. Whole-array WRITES are out of
scope for this PR — AdsTwinCATClient.WriteValueAsync returns
BadNotSupported when ArrayDimensions is set.

Tests: TwinCATArrayReadTests covers ResolveArrayShape (null / empty /
single-dim / multi-dim flatten / non-positive defensive), DiscoverAsync
emitting IsArray + ArrayDim for declared array tags, single-dim + multi-dim
fake-client read fan-out, and the BadNotSupported gate on whole-array
writes. Existing 137 unit tests still pass — total now 143.

Closes #308

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

@@ -22,22 +22,29 @@ public interface ITwinCATClient : IDisposable
     /// <summary>
     ///     Read a symbolic value. Returns a boxed .NET value matching the requested
     ///     <paramref name="type"/>, or <c>null</c> when the read produced no data; the
-    ///     <c>status</c> tuple member carries the mapped OPC UA status (0 = Good).
+    ///     <c>status</c> tuple member carries the mapped OPC UA status (0 = Good). When
+    ///     <paramref name="arrayDimensions"/> is non-null + non-empty, the symbol is treated
+    ///     as a whole-array read and the boxed value is a flat 1-D CLR
+    ///     <see cref="Array"/> sized to <c>product(arrayDimensions)</c>.
     /// </summary>
     Task<(object? value, uint status)> ReadValueAsync(
         string symbolPath,
         TwinCATDataType type,
         int? bitIndex,
+        int[]? arrayDimensions,
         CancellationToken cancellationToken);
 
     /// <summary>
     ///     Write a symbolic value. Returns the mapped OPC UA status for the operation
     ///     (0 = Good, non-zero = error mapped via <see cref="TwinCATStatusMapper"/>).
+    ///     <paramref name="arrayDimensions"/> mirrors <see cref="ReadValueAsync"/>; PR-1.4
+    ///     ships read-only whole-array support so writers may surface <c>BadNotSupported</c>.
     /// </summary>
     Task<uint> WriteValueAsync(
         string symbolPath,
         TwinCATDataType type,
         int? bitIndex,
+        int[]? arrayDimensions,
         object? value,
         CancellationToken cancellationToken);