Auto: ablegacy-8 — per-tag deadband / change filter

Closes #251

src/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/AbLegacyDriverFactoryExtensions.cs

@@ -52,7 +52,9 @@ public static class AbLegacyDriverFactoryExtensions
                         tagName: t.Name),
                     Writable: t.Writable ?? true,
                     WriteIdempotent: t.WriteIdempotent ?? false,
-                    ArrayLength: t.ArrayLength))]
+                    ArrayLength: t.ArrayLength,
+                    AbsoluteDeadband: t.AbsoluteDeadband,
+                    PercentDeadband: t.PercentDeadband))]
                 : [],
             Probe = new AbLegacyProbeOptions
             {
@@ -118,6 +120,20 @@ public static class AbLegacyDriverFactoryExtensions
         ///     driver issues a single contiguous PCCC block read for N elements.
         /// </summary>
         public int? ArrayLength { get; init; }
+
+        /// <summary>
+        ///     PR 8 — optional absolute change filter for numeric tags. <c>OnDataChange</c> is
+        ///     suppressed unless <c>|new - prev| &gt;= AbsoluteDeadband</c>. Booleans bypass;
+        ///     strings + status changes always publish.
+        /// </summary>
+        public double? AbsoluteDeadband { get; init; }
+
+        /// <summary>
+        ///     PR 8 — optional percent-of-previous change filter for numeric tags.
+        ///     <c>OnDataChange</c> is suppressed unless <c>|new - prev| &gt;= |prev * Percent / 100|</c>.
+        ///     <c>prev == 0</c> always publishes (avoids division-by-zero).
+        /// </summary>
+        public double? PercentDeadband { get; init; }
     }
 
     internal sealed class AbLegacyProbeDto