Merge master into feat/677-aggregates

# Conflicts:
#	docs/Historian.md

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway/GatewayHistorianDataSource.cs

@@ -125,6 +125,21 @@ public sealed class GatewayHistorianDataSource : IHistorianDataSource, IAsyncDis
         }
     }
 
+    /// <inheritdoc />
+    /// <remarks>
+    ///     A reverse (newest-first) read is refused with <see cref="NotSupportedException"/> — the server reports
+    ///     <c>BadHistoryOperationUnsupported</c> (Gitea #675). The gateway's <c>ReadEvents</c> streams ascending only and
+    ///     rejects <c>end &lt; start</c>, so the only way to serve "the latest N" would be to drain the whole window and
+    ///     keep its tail, an unbounded read the cap exists to prevent. Nothing is sent.
+    /// </remarks>
+    public Task<HistoricalEventsResult> ReadEventsAsync(
+        string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents, bool reverse,
+        CancellationToken cancellationToken) =>
+        reverse
+            ? throw new NotSupportedException(
+                "The HistorianGateway backend reads events oldest-first only; a reverse (newest-first) events read is not supported.")
+            : ReadEventsAsync(sourceName, startUtc, endUtc, maxEvents, cancellationToken);
+
     /// <inheritdoc />
     public async Task<HistoricalEventsResult> ReadEventsAsync(
         string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents,