feat(core): InputQuality.WorstOf — the one worst-of-input rule (archreview R3-02 contract)

src/Core/ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms/ScriptedAlarmEngine.cs

@@ -919,26 +919,18 @@ public sealed class ScriptedAlarmEngine : IDisposable
     /// the case the skip was hiding was the case that matters most. The upstream source now stamps a
     /// never-pushed path <see cref="StatusNeverPushed"/> and nothing else does, so the two are tellable
     /// apart. A null snapshot is still skipped: that is a cache the refill did not populate, not an
-    /// observation.</para></summary>
+    /// observation.</para>
+    /// <para><b>The comparison itself lives in <see cref="InputQuality.WorstOf"/></b> (archreview R3-02)
+    /// — the same rule the virtual-tag and Calculation seams now use, so "worst input wins, carrying its
+    /// sub-code, first-seen on a severity tie" is stated once. What stays here is the alarm-specific
+    /// <em>filter</em>: this engine's two skips are deliberately NOT part of the shared rule, because the
+    /// other two seams treat a never-pushed input as Bad rather than as absent.</para></summary>
     private static uint WorstInputStatus(IReadOnlyDictionary<string, DataValueSnapshot> cache)
     {
-        uint worst = 0u;
-        var worstSeverity = 0u;
-        foreach (var kv in cache)
-        {
-            // No entry at all — nothing was observed, so there is nothing to report on.
-            if (kv.Value is null) continue;
-            // Observed as "no data has ever arrived" — the cold-start placeholder, not a fault.
-            if (kv.Value.StatusCode == StatusNeverPushed) continue;
-            var status = kv.Value.StatusCode;
-            var severity = status >> 30;
-            if (severity > worstSeverity)
-            {
-                worstSeverity = severity;
-                worst = status;
-            }
-        }
-        return worst;
+        // No entry at all — nothing was observed, so there is nothing to report on.
+        // Observed as "no data has ever arrived" — the cold-start placeholder, not a fault.
+        var observed = cache.Values.Where(v => v is not null && v.StatusCode != StatusNeverPushed);
+        return InputQuality.WorstOf(observed);
     }
 
     /// <summary>Update the tracked worst-quality bucket for an alarm; return true iff the 3-state bucket