feat(opcua): HistoryReadEvents projects EventType, ConditionName, SourceNode; honours the where-clause (lmxopcua#746)

HistoryReadEvents projected only EventId / SourceName / Time / ReceiveTime /
Message / Severity: a select clause asking for EventType, ConditionName or
SourceNode (what most generic alarm viewers ask for) got nulls, and the
event filter's where-clause (an OfType) was ignored.

- HistoricalEvent gains optional EventTypeName, ConditionName and AlarmId.
  SqlServer, QuestDB and Gateway event reads fill them from what their
  alarm writers already store (AlarmTypeName / AlarmName / AlarmId; the
  gateway event Type and its AlarmName / AlarmId properties).
- The node manager maps the type name to its Part 9 event type (unknown or
  non-event => AlarmConditionType), projects ConditionName, and resolves
  SourceNode to the materialised condition the alarm id names (the live
  events' SourceNode), else null.
- The where-clause is evaluated per event with the SDK content filter
  through an IFilterTarget (OfType via the type tree; other operators
  against the projected fields), after the page's cursor is taken, so
  paging is unchanged.

Tested in the node manager, over a real client session (the Client.CLI has
no `historyread --events` mode yet; filed as a follow-up), and by alarm
writer -> event read round trips on SqlServer and QuestDB.

Rebased from the unpushed remed/lane-H2 branch (originally authored 2026-10-22
in session_01Ub9hGmYLQvn9XETzw7CMsT) onto current master.

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV

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

@@ -33,9 +33,16 @@ internal static class EventMapper
             EventTimeUtc: historianEvent.EventTime?.ToDateTime() ?? default,       // Utc kind
             ReceivedTimeUtc: historianEvent.ReceivedTime?.ToDateTime() ?? default, // Utc kind
             Message: message,
-            Severity: ParseSeverity(historianEvent.Properties));
+            Severity: ParseSeverity(historianEvent.Properties),
+            // What GatewayAlarmHistorianWriter sent (AlarmEventMapper): Type = AlarmTypeName, AlarmName / AlarmId properties.
+            EventTypeName: string.IsNullOrEmpty(historianEvent.Type) ? null : historianEvent.Type,
+            ConditionName: Property(historianEvent.Properties, "AlarmName"),
+            AlarmId: Property(historianEvent.Properties, "AlarmId"));
     }
 
+    private static string? Property(IDictionary<string, string> properties, string name) =>
+        properties.TryGetValue(name, out var v) && !string.IsNullOrEmpty(v) ? v : null;
+
     /// <summary>Maps a batch of gateway events to historical events, in order.</summary>
     /// <param name="events">The gateway wire events.</param>
     /// <returns>The driver-agnostic historical events.</returns>

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb/QuestDbHistorianDataSource.cs

@@ -449,7 +449,7 @@ public sealed class QuestDbHistorianDataSource : IHistorianDataSource
             var (lo, hi) = start <= end ? (start, end) : (end, start);
             var bounded = maxEvents > 0 && maxEvents < int.MaxValue;
             var sql =
-                $"SELECT event_id, source, ts, received_utc, message, severity FROM {_conn.EventTable} " +
+                $"SELECT event_id, source, ts, received_utc, message, severity, alarm_type_name, alarm_name, alarm_id FROM {_conn.EventTable} " +
                 (reverse ? "WHERE ts > $1 AND ts <= $2" : "WHERE ts >= $1 AND ts < $2") +
                 (sourceName is null ? "" : " AND source = $3") +
                 (reverse ? " ORDER BY ts DESC, event_id DESC" : " ORDER BY ts ASC, event_id ASC") +
@@ -474,7 +474,10 @@ public sealed class QuestDbHistorianDataSource : IHistorianDataSource
                     eventTime,
                     reader.IsDBNull(3) ? eventTime : QuestDbConnection.ReadUtc(reader, 3),
                     reader.IsDBNull(4) ? null : reader.GetString(4),
-                    HistoricalEventRows.ClampSeverity(reader.IsDBNull(5) ? 0 : reader.GetInt32(5)));
+                    HistoricalEventRows.ClampSeverity(reader.IsDBNull(5) ? 0 : reader.GetInt32(5)),
+                    EventTypeName: HistoricalEventRows.NullIfEmpty(reader.IsDBNull(6) ? null : reader.GetString(6)),
+                    ConditionName: HistoricalEventRows.NullIfEmpty(reader.IsDBNull(7) ? null : reader.GetString(7)),
+                    AlarmId: HistoricalEventRows.NullIfEmpty(reader.IsDBNull(8) ? null : reader.GetString(8)));
                 if (bounded && events.Count == maxEvents)
                 {
                     continuation = Encoding.UTF8.GetBytes(EventContinuation.Encode(e.EventTimeUtc, e.EventId));

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Sql.Common/HistoricalEventRows.cs

@@ -7,4 +7,9 @@ public static class HistoricalEventRows
     /// <param name="severity">Stored severity.</param>
     /// <returns>The severity clamped to 0..65535.</returns>
     public static ushort ClampSeverity(int severity) => (ushort)Math.Clamp(severity, 0, ushort.MaxValue);
+
+    /// <summary>A stored optional text column as the event carries it: empty (the writers' "none") is null.</summary>
+    /// <param name="value">The stored text.</param>
+    /// <returns>The text, or null when empty or absent.</returns>
+    public static string? NullIfEmpty(string? value) => string.IsNullOrEmpty(value) ? null : value;
 }

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer/SqlServerHistorianDataSource.cs

@@ -396,7 +396,7 @@ public sealed class SqlServerHistorianDataSource : IHistorianDataSource
             var (lo, hi) = startUtc <= endUtc ? (startUtc, endUtc) : (endUtc, startUtc);
             var bounded = maxEvents > 0 && maxEvents < int.MaxValue;
             var sql =
-                $"SELECT {(bounded ? "TOP (@take) " : "")}EventId, SourceName, EventTimeUtc, ReceivedTimeUtc, Message, Severity " +
+                $"SELECT {(bounded ? "TOP (@take) " : "")}EventId, SourceName, EventTimeUtc, ReceivedTimeUtc, Message, Severity, AlarmTypeName, AlarmName, AlarmId " +
                 $"FROM {_conn.Q("Event")} WHERE " +
                 (reverse ? "EventTimeUtc > @lo AND EventTimeUtc <= @hi" : "EventTimeUtc >= @lo AND EventTimeUtc < @hi") +
                 (sourceName is null ? "" : " AND SourceName = @source") +
@@ -421,7 +421,10 @@ public sealed class SqlServerHistorianDataSource : IHistorianDataSource
                     SqlHistorianConnection.GetUtc(reader, 2),
                     SqlHistorianConnection.GetUtc(reader, 3),
                     reader.IsDBNull(4) ? null : reader.GetString(4),
-                    HistoricalEventRows.ClampSeverity(reader.GetInt32(5)));
+                    HistoricalEventRows.ClampSeverity(reader.GetInt32(5)),
+                    EventTypeName: HistoricalEventRows.NullIfEmpty(reader.IsDBNull(6) ? null : reader.GetString(6)),
+                    ConditionName: HistoricalEventRows.NullIfEmpty(reader.IsDBNull(7) ? null : reader.GetString(7)),
+                    AlarmId: HistoricalEventRows.NullIfEmpty(reader.IsDBNull(8) ? null : reader.GetString(8)));
                 if (bounded && events.Count == maxEvents)
                 {
                     continuation = Encoding.UTF8.GetBytes(EventContinuation.Encode(e.EventTimeUtc, e.EventId));