feat(commons): native-typed JSON for List values; Decode reads both forms

tests/ZB.MOM.WW.ScadaBridge.Commons.Tests/Types/AttributeValueCodecTests.cs

@@ -64,7 +64,7 @@ public class AttributeValueCodecTests
         try
         {
             CultureInfo.CurrentCulture = new CultureInfo("de-DE");
-            Assert.Equal("[\"1.5\",\"2.5\"]",
+            Assert.Equal("[1.5,2.5]",
                 AttributeValueCodec.Encode(new List<double> { 1.5, 2.5 }));
         }
         finally
@@ -73,6 +73,53 @@ public class AttributeValueCodecTests
         }
     }
 
+    [Fact]
+    public void Encode_Int32List_ProducesNativeNumbers() =>
+        Assert.Equal("[10,20,30]",
+            AttributeValueCodec.Encode(new List<int> { 10, 20, 30 }));
+
+    [Fact]
+    public void Encode_BoolList_ProducesNativeBooleans() =>
+        Assert.Equal("[true,false]",
+            AttributeValueCodec.Encode(new List<bool> { true, false }));
+
+    [Fact]
+    public void Encode_StringList_StaysQuoted() =>
+        Assert.Equal("[\"a\",\"b\"]",
+            AttributeValueCodec.Encode(new List<string> { "a", "b" }));
+
+    [Fact]
+    public void Encode_DateTimeList_IsIso8601()
+    {
+        var json = AttributeValueCodec.Encode(
+            new List<DateTime> { new(2026, 6, 16, 0, 0, 0, DateTimeKind.Utc) });
+        Assert.Contains("2026-06-16T00:00:00", json);
+        Assert.DoesNotContain("06/16/2026", json);
+    }
+
+    [Fact]
+    public void Decode_NewNativeIntForm_Parses()
+    {
+        var back = (IList<int>)AttributeValueCodec.Decode("[10,20]", DataType.List, DataType.Int32)!;
+        Assert.Equal(new[] { 10, 20 }, back);
+    }
+
+    [Fact]
+    public void Decode_OldStringIntForm_BackwardCompatible()
+    {
+        var back = (IList<int>)AttributeValueCodec.Decode("[\"10\",\"20\"]", DataType.List, DataType.Int32)!;
+        Assert.Equal(new[] { 10, 20 }, back);
+    }
+
+    [Theory]
+    [InlineData("[true,false]")]
+    [InlineData("[\"True\",\"False\"]")]
+    public void Decode_BoolForms_BothParse(string json)
+    {
+        var back = (IList<bool>)AttributeValueCodec.Decode(json, DataType.List, DataType.Boolean)!;
+        Assert.Equal(new[] { true, false }, back);
+    }
+
     [Fact]
     public void RoundTrip_Int32List()
     {