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

Closes #251

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

@@ -22,9 +22,21 @@ public sealed record AbLegacyDeviceOptions(
     string? DeviceName = null);
 
 /// <summary>
-///     One PCCC-backed OPC UA variable. <paramref name="Address"/> is the canonical PCCC
-///     file-address string that parses via <see cref="AbLegacyAddress.TryParse(string?)"/>.
+///     One PCCC-backed OPC UA variable. <c>Address</c> is the canonical PCCC file-address
+///     string that parses via <see cref="AbLegacyAddress.TryParse(string?)"/>.
 /// </summary>
+/// <remarks>
+///     PR 8 deadband fields:
+///     <list type="bullet">
+///       <item><c>AbsoluteDeadband</c> — when set, suppresses <c>OnDataChange</c> for numeric
+///         tags unless <c>|new - prev| &gt;= AbsoluteDeadband</c>.</item>
+///       <item><c>PercentDeadband</c> — when set, suppresses unless
+///         <c>|new - prev| &gt;= |prev * Percent / 100|</c>; <c>prev == 0</c> always publishes.</item>
+///     </list>
+///     Booleans bypass deadband entirely (every transition publishes); strings + status
+///     changes always publish; first-seen always publishes; both set → logical-OR (Kepware
+///     semantics).
+/// </remarks>
 public sealed record AbLegacyTagDefinition(
     string Name,
     string DeviceHostAddress,
@@ -32,7 +44,9 @@ public sealed record AbLegacyTagDefinition(
     AbLegacyDataType DataType,
     bool Writable = true,
     bool WriteIdempotent = false,
-    int? ArrayLength = null);
+    int? ArrayLength = null,
+    double? AbsoluteDeadband = null,
+    double? PercentDeadband = null);
 
 public sealed class AbLegacyProbeOptions
 {