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/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