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.Configuration/LocalCache/ILocalConfigCache.cs

@@ -2,7 +2,7 @@ namespace ZB.MOM.WW.OtOpcUa.Configuration.LocalCache;
 
 /// <summary>
 ///     Per-node local cache of the most-recently-applied generation(s). Used to bootstrap the
-///     address space when the central DB is unreachable (decision #79 — degraded-but-running).
+///     address space when the central DB is unreachable (degraded-but-running).
 /// </summary>
 /// <remarks>
 ///     <para><b>Concurrency contract:</b> implementations must serialize writes — specifically,
@@ -21,10 +21,12 @@ public interface ILocalConfigCache
     /// <summary>Stores a generation snapshot in the local cache.</summary>
     /// <param name="snapshot">The generation snapshot to store.</param>
     /// <param name="ct">The cancellation token.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     Task PutAsync(GenerationSnapshot snapshot, CancellationToken ct = default);
     /// <summary>Removes old generations, keeping only the most recent N.</summary>
     /// <param name="clusterId">The cluster identifier.</param>
     /// <param name="keepLatest">The number of latest generations to keep.</param>
     /// <param name="ct">The cancellation token.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     Task PruneOldGenerationsAsync(string clusterId, int keepLatest = 10, CancellationToken ct = default);
 }