Expand XML docs across bridge and test code

tools/opcuacli-dotnet/OpcUaHelper.cs

@@ -6,6 +6,11 @@ namespace OpcUaCli;
 
 public static class OpcUaHelper
 {
+    /// <summary>
+    /// Creates an OPC UA client session for the specified endpoint URL.
+    /// </summary>
+    /// <param name="endpointUrl">The OPC UA endpoint URL to connect to.</param>
+    /// <returns>An active OPC UA client session.</returns>
     public static async Task<Session> ConnectAsync(string endpointUrl)
     {
         var config = new ApplicationConfiguration
@@ -61,6 +66,12 @@ public static class OpcUaHelper
 #pragma warning restore CS0618
     }
 
+    /// <summary>
+    /// Converts a raw command-line string 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.</param>
+    /// <returns>A typed value suitable for an OPC UA write request.</returns>
     public static object ConvertValue(string rawValue, object? currentValue)
     {
         return currentValue switch