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/Core/ZB.MOM.WW.OtOpcUa.Core/Observability/DriverHealthReport.cs

@@ -27,6 +27,7 @@ public static class DriverHealthReport
 {
     /// <summary>Compute the fleet-wide readiness verdict from per-driver states.</summary>
     /// <param name="drivers">The list of per-driver health snapshots to aggregate.</param>
+    /// <returns>The fleet-wide readiness verdict.</returns>
     public static ReadinessVerdict Aggregate(IReadOnlyList<DriverHealthSnapshot> drivers)
     {
         ArgumentNullException.ThrowIfNull(drivers);
@@ -54,6 +55,7 @@ public static class DriverHealthReport
     ///     return per the Stream C.1 state matrix.
     /// </summary>
     /// <param name="verdict">The readiness verdict to map to HTTP status.</param>
+    /// <returns>The HTTP status code the /readyz endpoint should return.</returns>
     public static int HttpStatus(ReadinessVerdict verdict) => verdict switch
     {
         ReadinessVerdict.Healthy => 200,

src/Core/ZB.MOM.WW.OtOpcUa.Core/Observability/LogContextEnricher.cs

@@ -11,7 +11,6 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Observability;
 ///     automatically via the Serilog enricher chain.
 /// </summary>
 /// <remarks>
-///     Per <c>docs/v2/implementation/phase-6-1-resilience-and-observability.md</c> §Stream C.2.
 ///     The correlation ID should be the OPC UA <c>RequestHeader.RequestHandle</c> when in-flight;
 ///     otherwise a short random GUID. Callers supply whichever is available.
 /// </remarks>
@@ -22,6 +21,7 @@ public static class LogContextEnricher
     /// <param name="driverType">The driver type name.</param>
     /// <param name="capability">The driver capability being invoked.</param>
     /// <param name="correlationId">The correlation ID for tracing the call.</param>
+    /// <returns>A disposable scope that pops the pushed properties when disposed.</returns>
     public static IDisposable Push(string driverInstanceId, string driverType, DriverCapability capability, string correlationId)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(driverInstanceId);
@@ -40,6 +40,7 @@ public static class LogContextEnricher
     ///     12-hex-char slice of a GUID — long enough for log correlation, short enough to
     ///     scan visually.
     /// </summary>
+    /// <returns>A 12-hex-character correlation ID.</returns>
     public static string NewCorrelationId() => Guid.NewGuid().ToString("N")[..12];
 
     private sealed class CompositeScope : IDisposable