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.FOCAS/FocasDriverFactoryExtensions.cs

@@ -205,6 +205,7 @@ public static class FocasDriverFactoryExtensions
     /// </summary>
     internal sealed class FlexibleStringConverter : JsonConverter<string?>
     {
+        /// <inheritdoc />
         public override string? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) =>
             reader.TokenType switch
             {
@@ -216,6 +217,7 @@ public static class FocasDriverFactoryExtensions
                 _ => throw new JsonException($"Expected string, number, or null but got {reader.TokenType}."),
             };
 
+        /// <inheritdoc />
         public override void Write(Utf8JsonWriter writer, string? value, JsonSerializerOptions options)
         {
             if (value is null) writer.WriteNullValue();