Merge ph-T4 (pluggable historian)

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

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

@@ -38,8 +38,6 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Recorder;
 /// </remarks>
 public sealed class GatewayHistorianValueWriter : IHistorianValueWriter, IAsyncDisposable
 {
-    private const uint LegacyGoodQuality = 192;
-
     private readonly IHistorianGatewayClient _client;
     private readonly ILogger<GatewayHistorianValueWriter> _logger;
 
@@ -70,12 +68,20 @@ public sealed class GatewayHistorianValueWriter : IHistorianValueWriter, IAsyncD
             var liveValues = new List<HistorianLiveValue>(values.Count);
             foreach (HistorizationValue value in values)
             {
+                if (!value.Value.TryGetDouble(out double number))
+                {
+                    // The gateway live path is numeric-only; non-numeric kinds are skipped, never thrown.
+                    _logger.LogDebug("Skipping non-numeric {Kind} value for live write.", value.Value.Kind);
+                    continue;
+                }
+
                 var live = new HistorianLiveValue
                 {
-                    NumericValue = value.Value.Number,
+                    NumericValue = number,
                     // Documented-dead input on the WriteLiveValues SQL path (0.2.0 Contracts C-002 —
-                    // server-managed, silently discarded). Populated deliberately; see the class <remarks>.
-                    Quality = LegacyGoodQuality,
+                    // server-managed, silently discarded). Populated deliberately from the value's
+                    // status; Good maps to 192 as before. See the class <remarks>.
+                    Quality = Mapping.GatewayQualityMapper.ToDaQuality(value.StatusCode),
                 };
 
                 if (value.TimestampUtc is { } timestampUtc)
@@ -88,6 +94,12 @@ public sealed class GatewayHistorianValueWriter : IHistorianValueWriter, IAsyncD
                 liveValues.Add(live);
             }
 
+            if (liveValues.Count == 0)
+            {
+                // Every value was non-numeric: nothing to send, trivially drained.
+                return true;
+            }
+
             WriteAck ack = await _client.WriteLiveValuesAsync(tag, liveValues, ct).ConfigureAwait(false);
             return ack.Success || ack.Queued;
         }