feat(alarms): EquipmentTagPlan.Alarm parsed byte-parity from TagConfig (Phase B WS-2)

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DeploymentArtifact.cs

@@ -445,7 +445,8 @@ public static class DeploymentArtifact
                 Name: name!,
                 DataType: dataType ?? "BaseDataType",
                 FullName: ExtractTagFullName(tagConfig),
-                Writable: writable));
+                Writable: writable,
+                Alarm: ExtractTagAlarm(tagConfig)));
         }
 
         result.Sort((a, b) =>
@@ -651,6 +652,26 @@ public static class DeploymentArtifact
         return tagConfig;
     }
 
+    /// <summary>Parses the optional <c>alarm</c> object from a tag's <c>TagConfig</c> JSON. Returns null
+    /// when absent, non-object, or non-JSON (the tag is then a plain variable). Never throws. The
+    /// live-edit side (<c>Phase7Composer.ExtractTagAlarm</c>) MUST parse identically (byte-parity).</summary>
+    private static EquipmentTagAlarmInfo? ExtractTagAlarm(string? tagConfig)
+    {
+        if (string.IsNullOrWhiteSpace(tagConfig)) return null;
+        try
+        {
+            using var doc = JsonDocument.Parse(tagConfig);
+            if (doc.RootElement.ValueKind != JsonValueKind.Object) return null;
+            if (!doc.RootElement.TryGetProperty("alarm", out var a) || a.ValueKind != JsonValueKind.Object) return null;
+            var type = a.TryGetProperty("alarmType", out var tEl) && tEl.ValueKind == JsonValueKind.String
+                ? (tEl.GetString() ?? "AlarmCondition") : "AlarmCondition";
+            var sev = a.TryGetProperty("severity", out var sEl) && sEl.ValueKind == JsonValueKind.Number
+                ? sEl.GetInt32() : 500;
+            return new EquipmentTagAlarmInfo(type, sev);
+        }
+        catch (JsonException) { return null; }
+    }
+
     private static IReadOnlyList<T> ReadArray<T>(JsonElement root, string propertyName, Func<JsonElement, T?> reader)
         where T : class
     {