Add cross-platform OPC UA client stack: shared library, CLI tool, and Avalonia UI

Implements Client.Shared (IOpcUaClientService with connection lifecycle, failover,
browse, read/write, subscriptions, alarms, history, redundancy), Client.CLI (8 CliFx
commands mirroring tools/opcuacli-dotnet), and Client.UI (Avalonia desktop app with
tree browser, read/write, subscriptions, alarms, and history tabs). All three target
.NET 10 and are covered by 249 unit tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.LmxOpcUa.Client.Shared/Helpers/ValueConverter.cs

@@ -0,0 +1,32 @@
+namespace ZB.MOM.WW.LmxOpcUa.Client.Shared.Helpers;
+
+/// <summary>
+/// Converts raw string values into typed values based on the current value's runtime type.
+/// Ported from the CLI tool's OpcUaHelper.ConvertValue.
+/// </summary>
+public static class ValueConverter
+{
+    /// <summary>
+    /// Converts a raw string value into the runtime type expected by the target node.
+    /// </summary>
+    /// <param name="rawValue">The raw string supplied by the user.</param>
+    /// <param name="currentValue">The current node value used to infer the target type. May be null.</param>
+    /// <returns>A typed value suitable for an OPC UA write request.</returns>
+    public static object ConvertValue(string rawValue, object? currentValue)
+    {
+        return currentValue switch
+        {
+            bool => bool.Parse(rawValue),
+            byte => byte.Parse(rawValue),
+            short => short.Parse(rawValue),
+            ushort => ushort.Parse(rawValue),
+            int => int.Parse(rawValue),
+            uint => uint.Parse(rawValue),
+            long => long.Parse(rawValue),
+            ulong => ulong.Parse(rawValue),
+            float => float.Parse(rawValue),
+            double => double.Parse(rawValue),
+            _ => rawValue
+        };
+    }
+}