docs(code): honest rationales — Akka restart semantics, per-key shards, EF literal inlining; retire or annotate orphaned members

src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/IHistorizationOutbox.cs

@@ -13,7 +13,16 @@ public interface IHistorizationOutbox : IDisposable
     /// <summary>Lifetime count of entries dropped because an append would have exceeded capacity.</summary>
     long DroppedCount { get; }
 
-    /// <summary>Appends <paramref name="entry"/> to the tail of the durable buffer.</summary>
+    /// <summary>
+    ///     Appends <paramref name="entry"/> to the tail of the durable buffer.
+    ///     <para>
+    ///         <b>Retained for tests and direct callers; production appends only through
+    ///         <see cref="AppendBatchAsync"/>.</b> The recorder coalesces a driver burst into one group
+    ///         commit, so this single-entry form has no production call site — it is kept as the
+    ///         one-entry expression of the same contract (and is what <see cref="AppendBatchAsync"/>'s
+    ///         durability window is described against), not as a deprecated path.
+    ///     </para>
+    /// </summary>
     /// <param name="entry">The value record to buffer.</param>
     /// <param name="ct">Cancellation token.</param>
     /// <returns>A task that represents the asynchronous operation.</returns>

src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/IHistorizedTagSubscriptionSink.cs

@@ -5,9 +5,11 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 ///     because a <c>HistorianTagname</c> override makes them diverge:
 ///     <list type="bullet">
 ///       <item>
-///         <see cref="MuxRef"/> — the driver-published reference the per-node dependency mux fans its
-///         <c>DependencyValueChanged</c> by (the tag's driver-side <c>FullName</c>). The recorder
-///         registers mux interest and matches incoming values by THIS.
+///         <see cref="MuxRef"/> — the driver-published reference the per-node dependency mux fans values
+///         by (the tag's driver-side <c>FullName</c>); in production those arrive as a
+///         <c>DependencyValueBatch</c> per driver burst, with the per-value <c>DependencyValueChanged</c>
+///         retained for direct senders and tests. The recorder registers mux interest and matches
+///         incoming values by THIS.
 ///       </item>
 ///       <item>
 ///         <see cref="HistorianName"/> — the resolved historian tag name the value is written under (a