feat(engines): IVirtualTagEvaluator snapshot overload; Roslyn read cache stops fabricating Good (02/S14)

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Engines/IVirtualTagEvaluator.cs

@@ -1,3 +1,5 @@
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
 namespace ZB.MOM.WW.OtOpcUa.Commons.Engines;
 
 /// <summary>
@@ -18,6 +20,34 @@ public interface IVirtualTagEvaluator
     /// <param name="dependencies">Read-only dictionary of variable names to values for expression evaluation.</param>
     /// <returns>Result containing success flag, evaluated value, and optional failure reason.</returns>
     VirtualTagEvalResult Evaluate(string virtualTagId, string expression, IReadOnlyDictionary<string, object?> dependencies);
+
+    /// <summary>
+    ///     Evaluate <paramref name="expression"/> against dependency <b>snapshots</b> — value, status
+    ///     code and source timestamp per input — so a script's <c>ctx.GetTag(path).StatusCode</c> reports
+    ///     what the source actually said (archreview 02/S14).
+    /// </summary>
+    /// <remarks>
+    ///     <b>Default-implemented on purpose.</b> It projects to values and calls the older overload, so
+    ///     every existing implementation — the Roslyn evaluator aside, that is the null evaluator and the
+    ///     test fakes — compiles and behaves unchanged; an implementation that can do better (the Roslyn
+    ///     one) overrides it. Making it abstract would have been a breaking change for a fix whose whole
+    ///     point is that it changes nothing on the Good path.
+    ///     <para>The default necessarily discards the status codes it was given, which is exactly the
+    ///     laundering this overload exists to end — so a consumer that cares must call an implementation
+    ///     that overrides it.</para>
+    /// </remarks>
+    /// <param name="virtualTagId">The unique identifier of the virtual tag being evaluated.</param>
+    /// <param name="expression">The expression string to evaluate.</param>
+    /// <param name="dependencies">Read-only dictionary of dependency snapshots, keyed by tag path.</param>
+    /// <returns>Result containing success flag, evaluated value, and optional failure reason.</returns>
+    VirtualTagEvalResult Evaluate(
+        string virtualTagId, string expression, IReadOnlyDictionary<string, DataValueSnapshot> dependencies)
+    {
+        ArgumentNullException.ThrowIfNull(dependencies);
+        var values = new Dictionary<string, object?>(dependencies.Count, StringComparer.Ordinal);
+        foreach (var kv in dependencies) values[kv.Key] = kv.Value?.Value;
+        return Evaluate(virtualTagId, expression, values);
+    }
 }
 
 /// <summary>Result of one virtual-tag expression eval. Stash a Reason on every Failure so