Auto: abcip-2.3 — descriptions to OPC UA Description

Threads tag/UDT-member descriptions captured by the L5K (#346) and L5X
(#347) parsers through AbCipTagDefinition + AbCipStructureMember into
DriverAttributeInfo, so the address-space builder sets the OPC UA
Description attribute on each Variable node. L5kMember and L5xParser
also now capture per-member descriptions (via the (Description := "...")
attribute block on L5K and the <Description> child on L5X), and
L5kIngest forwards them. DriverNodeManager surfaces
DriverAttributeInfo.Description as the Variable's Description property.

Description is added as a trailing optional parameter on
DriverAttributeInfo (default null) so every other driver continues
to construct the record unchanged.

Closes #231

src/ZB.MOM.WW.OtOpcUa.Driver.AbCip/Import/L5kIngest.cs

@@ -55,7 +55,11 @@ public sealed class L5kIngest
                 var atomic = TryMapAtomic(m.DataType);
                 var memberType = atomic ?? AbCipDataType.Structure;
                 var writable = !IsReadOnly(m.ExternalAccess) && !IsAccessNone(m.ExternalAccess);
-                members.Add(new AbCipStructureMember(m.Name, memberType, writable));
+                members.Add(new AbCipStructureMember(
+                    Name: m.Name,
+                    DataType: memberType,
+                    Writable: writable,
+                    Description: m.Description));
             }
             udtIndex[dt.Name] = members;
         }
@@ -101,7 +105,8 @@ public sealed class L5kIngest
                 TagPath: tagPath,
                 DataType: dataType,
                 Writable: writable,
-                Members: members));
+                Members: members,
+                Description: t.Description));
         }
 
         return new L5kIngestResult(tags, skippedAliases, skippedNoAccess);

src/ZB.MOM.WW.OtOpcUa.Driver.AbCip/Import/L5kParser.cs

@@ -311,7 +311,8 @@ public static class L5kParser
 
         if (typePart.Length == 0) return null;
         var externalAccess = attributes.TryGetValue("ExternalAccess", out var ea) ? ea.Trim() : null;
-        return new L5kMember(name, typePart, arrayDim, externalAccess);
+        var description = attributes.TryGetValue("Description", out var d) ? Unquote(d) : null;
+        return new L5kMember(name, typePart, arrayDim, externalAccess, description);
     }
 
     // ---- helpers -----------------------------------------------------------
@@ -377,4 +378,9 @@ public sealed record L5kTag(
 public sealed record L5kDataType(string Name, IReadOnlyList<L5kMember> Members);
 
 /// <summary>One member line inside a UDT definition.</summary>
-public sealed record L5kMember(string Name, string DataType, int? ArrayDim, string? ExternalAccess);
+public sealed record L5kMember(
+    string Name,
+    string DataType,
+    int? ArrayDim,
+    string? ExternalAccess,
+    string? Description = null);

src/ZB.MOM.WW.OtOpcUa.Driver.AbCip/Import/L5xParser.cs

@@ -163,11 +163,21 @@ public static class L5xParser
             arrayDim = dim;
         }
 
+        // Description child — same shape as on Tag nodes; sometimes wrapped in CDATA.
+        string? description = null;
+        var descNode = memberNode.SelectSingleNode("Description");
+        if (descNode is not null)
+        {
+            var raw = descNode.Value;
+            if (!string.IsNullOrEmpty(raw)) description = raw.Trim();
+        }
+
         return new L5kMember(
             Name: name,
             DataType: dataType,
             ArrayDim: arrayDim,
-            ExternalAccess: string.IsNullOrEmpty(externalAccess) ? null : externalAccess);
+            ExternalAccess: string.IsNullOrEmpty(externalAccess) ? null : externalAccess,
+            Description: description);
     }
 
     private static L5kDataType? ReadAddOnInstruction(XPathNavigator aoiNode)
@@ -200,11 +210,20 @@ public static class L5xParser
                 arrayDim = dim;
             }
 
+            string? paramDescription = null;
+            var paramDescNode = paramNode.SelectSingleNode("Description");
+            if (paramDescNode is not null)
+            {
+                var raw = paramDescNode.Value;
+                if (!string.IsNullOrEmpty(raw)) paramDescription = raw.Trim();
+            }
+
             members.Add(new L5kMember(
                 Name: paramName,
                 DataType: dataType,
                 ArrayDim: arrayDim,
-                ExternalAccess: string.IsNullOrEmpty(externalAccess) ? null : externalAccess));
+                ExternalAccess: string.IsNullOrEmpty(externalAccess) ? null : externalAccess,
+                Description: paramDescription));
         }
         return new L5kDataType(name, members);
     }