fix(template-engine): resolve TemplateEngine-011,013,014 — remove dead converter, duplicate-id-safe cycle detection, unified deletion logic; TemplateEngine-012 deferred

tests/ScadaLink.TemplateEngine.Tests/Flattening/RevisionHashServiceTests.cs

@@ -99,6 +99,38 @@ public class RevisionHashServiceTests
         Assert.Equal(_sut.ComputeHash(config1), _sut.ComputeHash(config2));
     }
 
+    [Fact]
+    public void HashableRecords_PropertiesDeclaredAlphabetically()
+    {
+        // TemplateEngine-011: revision-hash determinism depends entirely on the
+        // private Hashable* records declaring their properties in alphabetical
+        // order (System.Text.Json emits properties in CLR declaration order and
+        // does not sort). This guards against a contributor silently changing
+        // every revision hash by adding a property out of order.
+        var nested = typeof(RevisionHashService)
+            .GetNestedTypes(System.Reflection.BindingFlags.NonPublic)
+            .Where(t => t.Name.StartsWith("Hashable"))
+            .ToList();
+
+        Assert.NotEmpty(nested);
+
+        foreach (var type in nested)
+        {
+            var propNames = type
+                .GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance)
+                .Where(p => p.Name != "EqualityContract")
+                .Select(p => p.Name)
+                .ToList();
+
+            var sorted = propNames.OrderBy(n => n, StringComparer.Ordinal).ToList();
+
+            Assert.True(
+                propNames.SequenceEqual(sorted),
+                $"{type.Name} properties must be declared alphabetically. " +
+                $"Declared: [{string.Join(", ", propNames)}] Expected: [{string.Join(", ", sorted)}]");
+        }
+    }
+
     private static FlattenedConfiguration CreateConfig(string instanceName, string tempValue)
     {
         return new FlattenedConfiguration