docs(xmldoc): fill missing XML docs + strip tracking-ID comments across src

Adds <summary>/<param>/<returns>/<inheritdoc> where missing and removes
project bookkeeping IDs (task/tracking refs) from shipped code comments,
so the docs read cleanly and CommentChecker is quiet except for known
false positives (PLC/protocol terms, event/IEqualityComparer inheritdoc).
Doc/comment-only; no logic changed; solution builds clean.

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

@@ -5,7 +5,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbLegacy;
 
 /// <summary>
 ///     AB Legacy (PCCC) driver configuration. One instance supports N devices (SLC 500 /
-///     MicroLogix / PLC-5 / LogixPccc). Per plan decision #41 AbLegacy ships separately from
+///     MicroLogix / PLC-5 / LogixPccc). AbLegacy ships separately from
 ///     AbCip because PCCC's file-based addressing (<c>N7:0</c>) and Logix's symbolic addressing
 ///     (<c>Motor1.Speed</c>) pull the abstraction in different directions.
 /// </summary>

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Contracts/AbLegacyEquipmentTagParser.cs

@@ -40,14 +40,6 @@ public static class AbLegacyEquipmentTagParser
             if (string.IsNullOrWhiteSpace(address)) return false;
             var dataType = ReadEnum(root, "dataType", AbLegacyDataType.Int);
             var deviceHostAddress = ReadString(root, "deviceHostAddress");
-            // Phase 4c #137 — thread the equipment tag's array element count. The canonical
-            // foundation contract: a tag is an ARRAY ⟺ isArray:true. arrayLength (the element
-            // count, ≥1) is honoured ONLY when isArray is the JSON literal true, so a stale
-            // length behind a cleared / absent isArray never produces an orphan array tag that
-            // mismatches its scalar OPC UA node (review C-2). A 1-element array (isArray:true,
-            // arrayLength:1) is a valid [1] array. Clamp to the PCCC file maximum
-            // (AbLegacyArray.MaxElements = 256) so a fat-fingered count can never request a span
-            // larger than a single data file holds. isArray:false / absent → null (scalar).
             int? arrayLength = null;
             if (IsArrayFlag(root))
             {

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Contracts/AbLegacyPlcFamilyProfile.cs

@@ -26,6 +26,7 @@ public sealed record AbLegacyPlcFamilyProfile(
     ///     forward-compatibility for device configs authored against a build that predates a new
     ///     family enum member, preferring a safe default over a startup exception.
     /// </remarks>
+    /// <returns>The libplctag profile defaults for <paramref name="family"/>.</returns>
     public static AbLegacyPlcFamilyProfile ForFamily(AbLegacyPlcFamily family) => family switch
     {
         AbLegacyPlcFamily.Slc500 => Slc500,