feat(historian): #691 HistoryRead-Raw ReturnBounds — Part 11 bounding values on every backend

The node manager composes the start/end bounds from each backend's existing raw
reads (one authority, HistoryBounds): at-or-before = a capped reverse read
(native, or ReverseRawReader's walk-back on a forward-only backend — never
AVEVA's synthetic boundary row), at-or-after = a capped forward read. Bounds
count toward NumValuesPerNode, the start bound leads the first page, the end
bound ends the last (carried in the continuation point). Missing bound =
Bad_BoundNotFound (null, at the bound time; one-sided reads ±1 s from the
previous value, Table 1 footnotes a/b). A modified read with ReturnBounds is
Bad_InvalidArgument (Part 11 6.5.3.3).

The .NET SDK's ReadRawModifiedDetails defaults ReturnBounds to TRUE; the
existing tests built details without setting it and now set it false.
Oracle: every row of Part 11 Table 1 over three backend shapes, plus paging
concatenation, ties, Bad bounds, microsecond truncation; conformance pins the
lookup primitives on SqlServer + QuestDB.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/NodeManagerHistoryReadEventsPagingTests.cs

@@ -160,7 +160,7 @@ public sealed class NodeManagerHistoryReadEventsPagingTests : IDisposable
             var ctx = new OperationContext(new RequestHeader(), secureChannelContext: null, RequestType.HistoryRead, identity: null);
             var res = new List<SdkHistoryReadResult> { null! };
             var errs = new List<ServiceResult> { null! };
-            nm.HistoryRead(ctx, new ReadRawModifiedDetails { StartTime = Epoch, EndTime = Epoch.AddHours(1), NumValuesPerNode = 2, IsReadModified = false },
+            nm.HistoryRead(ctx, new ReadRawModifiedDetails { ReturnBounds = false, StartTime = Epoch, EndTime = Epoch.AddHours(1), NumValuesPerNode = 2, IsReadModified = false },
                 TimestampsToReturn.Both, false,
                 new List<HistoryReadValueId> { new() { NodeId = n, ContinuationPoint = cp } }, res, errs);
             err = errs[0];