fix(uns): omit blank optional keys from TagConfig + add omission tests; drop unused ParseInt (T4-T8 review)

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/AbCipTagConfigEditor.razor

@@ -28,8 +28,6 @@
         _m = AbCipTagConfigModel.FromJson(ConfigJson);
     }
 
-    private static int ParseInt(object? v, int fallback = 0) => int.TryParse(v?.ToString(), out var i) ? i : fallback;
-
     // TryParse so a bad/empty change value can never throw into the Blazor circuit — it falls back.
     private static TEnum ParseEnum<TEnum>(object? v, TEnum fallback) where TEnum : struct, Enum
         => Enum.TryParse<TEnum>(v?.ToString(), out var r) ? r : fallback;

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/AbLegacyTagConfigEditor.razor

@@ -28,8 +28,6 @@
         _m = AbLegacyTagConfigModel.FromJson(ConfigJson);
     }
 
-    private static int ParseInt(object? v, int fallback = 0) => int.TryParse(v?.ToString(), out var i) ? i : fallback;
-
     // TryParse so a bad/empty change value can never throw into the Blazor circuit — it falls back.
     private static TEnum ParseEnum<TEnum>(object? v, TEnum fallback) where TEnum : struct, Enum
         => Enum.TryParse<TEnum>(v?.ToString(), out var r) ? r : fallback;

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/FocasTagConfigEditor.razor

@@ -28,8 +28,6 @@
         _m = FocasTagConfigModel.FromJson(ConfigJson);
     }
 
-    private static int ParseInt(object? v, int fallback = 0) => int.TryParse(v?.ToString(), out var i) ? i : fallback;
-
     // TryParse so a bad/empty change value can never throw into the Blazor circuit — it falls back.
     private static TEnum ParseEnum<TEnum>(object? v, TEnum fallback) where TEnum : struct, Enum
         => Enum.TryParse<TEnum>(v?.ToString(), out var r) ? r : fallback;

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/TwinCATTagConfigEditor.razor

@@ -28,8 +28,6 @@
         _m = TwinCATTagConfigModel.FromJson(ConfigJson);
     }
 
-    private static int ParseInt(object? v, int fallback = 0) => int.TryParse(v?.ToString(), out var i) ? i : fallback;
-
     // TryParse so a bad/empty change value can never throw into the Blazor circuit — it falls back.
     private static TEnum ParseEnum<TEnum>(object? v, TEnum fallback) where TEnum : struct, Enum
         => Enum.TryParse<TEnum>(v?.ToString(), out var r) ? r : fallback;

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/TagConfigJson.cs

@@ -33,7 +33,10 @@ public static class TagConfigJson
     public static TEnum GetEnum<TEnum>(JsonObject o, string name, TEnum fallback) where TEnum : struct, Enum
         => GetString(o, name) is { } s && Enum.TryParse<TEnum>(s, ignoreCase: true, out var v) ? v : fallback;
 
-    /// <summary>Sets a string/number/enum-name value (enums via ToString()). Null removes the key.</summary>
+    /// <summary>Sets a string/number/enum-name value (enums via ToString()). A null value REMOVES the key, so it is omitted from the serialised JSON.</summary>
     public static void Set(JsonObject o, string name, object? value)
-        => o[name] = value is null ? null : JsonValue.Create(value is Enum e ? e.ToString() : value);
+    {
+        if (value is null) { o.Remove(name); return; }
+        o[name] = JsonValue.Create(value is Enum e ? e.ToString() : value);
+    }
 }