fix(ablegacy): Test Connect normalises the probe address like the driver (#660)

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/AbLegacyDriver.cs

@@ -693,7 +693,7 @@ public sealed class AbLegacyDriver : IDriver, IReadable, IWritable, ITagDiscover
             LibplctagPlcAttribute: state.Profile.LibplctagPlcAttribute,
             // Normalised exactly like tag paths (PLC-5 octal I/O -> decimal); an unparseable probe address is passed through
             // so the transport reports the failure as it always did.
-            TagName: AbLegacyAddress.TryParse(_options.Probe.ProbeAddress, state.Options.PlcFamily)?.ToLibplctagName()
+            TagName: AbLegacyProbeAddress.Normalise(_options.Probe.ProbeAddress, state.Options.PlcFamily)
                      ?? _options.Probe.ProbeAddress!,
             Timeout: _options.Probe.Timeout);
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/AbLegacyDriverProbe.cs

@@ -98,12 +98,18 @@ public sealed class AbLegacyDriverProbe : IDriverProbe
             ?? FirstProbeableTagAddress(opts, firstDevice)
             ?? "S:0";
 
+        // Normalise through the same helper as the driver's probe loop (#660): PLC-5 octal I/O -> decimal.
+        // An unparseable address is a clean failure here — the factory would otherwise throw outside the try.
+        var normalisedName = AbLegacyProbeAddress.Normalise(tagName, firstDevice?.PlcFamily ?? AbLegacyPlcFamily.Slc500);
+        if (normalisedName is null)
+            return new(false, $"Probe address '{tagName}' is not a valid AbLegacy address for this PLC family.", null);
+
         var p = new AbLegacyTagCreateParams(
             Gateway: parsed.Gateway,
             Port: parsed.Port,
             CipPath: parsed.CipPath,
             LibplctagPlcAttribute: profile.LibplctagPlcAttribute,
-            TagName: tagName,
+            TagName: normalisedName,
             Timeout: timeout);
 
         var factory = _tagFactory ?? (AbLegacyTransportResolver.Resolve(opts) == AbLegacyTransport.Native

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/AbLegacyProbeAddress.cs

@@ -0,0 +1,16 @@
+using ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.PlcFamilies;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.AbLegacy;
+
+/// <summary>
+///     The single authority that turns an operator-authored probe address into the name handed to the tag
+///     factory: family-aware parse (PLC-5 <c>I:</c>/<c>O:</c> octal indices become decimal) then
+///     <see cref="AbLegacyAddress.ToLibplctagName"/> — the same normalisation tag paths get. Shared by the
+///     driver's probe loop and the Test Connect probe (#660).
+/// </summary>
+internal static class AbLegacyProbeAddress
+{
+    /// <summary>Returns the normalised name, or null when <paramref name="address"/> does not parse for the family.</summary>
+    public static string? Normalise(string? address, AbLegacyPlcFamily family) =>
+        AbLegacyAddress.TryParse(address, family)?.ToLibplctagName();
+}