fix(ablegacy): deterministic NotSupported refusals are BadNotSupported with no health write

Review 07 H16: an array of String/Timer/Counter/Control passed the mapper, so
every poll created a handle (one init read), the decode threw
NotSupportedException, the generic catch evicted the handle and latched
Degraded. FromTagConfig now rejects that combination (the skip carries the
reason, Inspect/deploy gate and the AdminUI model state it), and a runtime
NotSupportedException on read or write is BadNotSupported: handle kept, no
health write, one Warning per tag and operation. Write refusals (native PLC-5
and status-bit writes, libplctag translated addresses) now warn once per tag too.

Refs #738
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/AbLegacyTagConfigModelTests.cs

@@ -122,6 +122,20 @@ public sealed class AbLegacyTagConfigModelTests
         m.Validate().ShouldBeNull();
     }
 
+    /// <summary>Review 07 H16: an array of a structured element type is refused with the reader's own reason.</summary>
+    [Theory]
+    [InlineData("String", "ST9:0")]
+    [InlineData("TimerElement", "T4:0")]
+    public void Validate_refuses_an_array_of_a_structured_element_type(string dataType, string address)
+    {
+        var m = AbLegacyTagConfigModel.FromJson(
+            $$"""{"address":"{{address}}","dataType":"{{dataType}}","isArray":true,"arrayLength":4}""");
+
+        m.Validate().ShouldNotBeNull().ShouldContain("not supported as an array");
+        // Positive control: the same type as a scalar validates.
+        AbLegacyTagConfigModel.FromJson($$"""{"address":"{{address}}","dataType":"{{dataType}}"}""").Validate().ShouldBeNull();
+    }
+
     [Fact]
     public void Validate_returns_null_for_scalar_tag_regardless_of_no_array_length()
     {