fix(abcip,adminui): ParseEnum device wording + libplctag probe assertion (#574); AB forms preserve unknown keys + MaxConcurrentReads (#576); probe off for new AbCip driver (#577); docs T4:0.DN (#584)

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

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip.Tests/AbCipTransportSwitchTests.cs

@@ -64,6 +64,9 @@ public sealed class AbCipTransportSwitchTests
             "ab1", """{"devices":[{"hostAddress":"ab://10.0.0.1/1,0","plcFamily":"Bogus"}]}"""));
         existing.GetType().ShouldBe(bad.GetType());
         existing.Message.ShouldContain("unknown PlcFamily 'Bogus'");
+        // #574: a device-level field must not be reported as a tag named 'device'.
+        existing.Message.ShouldNotContain("tag '");
+        existing.Message.ShouldStartWith("AB CIP config in 'ab1' has unknown PlcFamily 'Bogus'");
     }
 
     /// <summary>
@@ -145,6 +148,9 @@ public sealed class AbCipTransportSwitchTests
         native.Message.ShouldNotBeNull();
         native.Message!.ShouldContain("CIP handshake failed: Connection lost");
         lib.Message!.ShouldNotContain("Connection lost");
+        // Positive (#574): the libplctag path ran and reported its own outcome (the bounded probe timeout),
+        // not merely "something other than the native text".
+        lib.Message!.ShouldContain("timed out");
     }
 
     /// <summary>
@@ -180,6 +186,9 @@ public sealed class AbCipTransportSwitchTests
         absent.Ok.ShouldBeFalse();
         absent.Message!.ShouldContain("CIP handshake failed: Connection lost");
         lib.Message!.ShouldNotContain("Connection lost");
+        // Positive (#574): the libplctag path ran and reported its own outcome (the bounded probe timeout),
+        // not merely "something other than the native text".
+        lib.Message!.ShouldContain("timed out");
     }
 
     /// <summary>The probe deserialises with its own string-enum converter; a bad transport is a config error.</summary>
@@ -259,5 +268,6 @@ public sealed class AbCipTransportSwitchTests
         unpinned.Message!.ShouldContain("CIP handshake failed: Connection lost");
         pinned.Ok.ShouldBeFalse();
         pinned.Message!.ShouldNotContain("Connection lost");
+        pinned.Message!.ShouldContain("timed out"); // positive: libplctag's own outcome (#574)
     }
 }