fix(opcuaclient): register the OpcUaClient driver factory (was always stubbed)

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient/OpcUaClientDriverProbe.cs

@@ -17,10 +17,14 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient;
 /// </summary>
 public sealed class OpcUaClientDriverProbe : IDriverProbe
 {
+    // Kept identical to OpcUaClientDriverFactoryExtensions.JsonOptions so the probe and the
+    // factory parse a given DriverConfig the same way. The JsonStringEnumConverter lets
+    // enum-valued knobs be authored as their string names.
     private static readonly JsonSerializerOptions _opts = new()
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />