fix(historian): #683 review — bound the StartEnd pick joins to the window; usable picks re-check usability

- SqlServer StartEnd join-back: every pick join also carries the window predicate
  (forward >= @start AND < @end, reverse > @start AND <= @end). Keyed on the pick
  time alone a hash/merge/adaptive join read the tag's whole history (review:
  43,657 vs 361 logical reads), and parameter sniffing reused that plan for every
  tag. Forced OPTION (HASH JOIN), 1d@1h on 6M rows: 152,524 -> 6,756 reads.
- Usable picks (x/y) re-check the exact u predicate in the join, so a concurrent
  HistoryUpdate Replace that turned the picked sample Bad/Empty reads as absent
  (BadNoData), never a Bad row's value under Delta.
- StartEndJoinBackTests (integration): 300k history rows either side of a 1 h
  window, forced HASH and MERGE joins, results identical to the unhinted plan and
  Start/End correct, session logical reads < 1,000 (183 bounded; 8,055 with the
  bound removed — the test fails then).
- TagIndexTests: the refused-ADD-INDEX test asserts the Warning naming the ALTER.
- Historian.md: re-measured table incl. long-history windows (output identical by
  EXCEPT both ways in all 7 cases) and the forced-join read counts.

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.QuestDb.IntegrationTests/TagIndexTests.cs

@@ -100,7 +100,24 @@ public sealed class TagIndexTests(QuestDbFixture fx)
             await using var alter = conn.CreateCommand(c, QuestDbTables.AddTagIndex(conn.SampleTable));
             await Should.ThrowAsync<Exception>(() => alter.ExecuteNonQueryAsync(Ct)); // precondition: really refused
         }
-        await new QuestDbSchemaBootstrapper(conn, o).EnsureAsync(Ct);
+        var log = new ListLogger();
+        await new QuestDbSchemaBootstrapper(conn, o, log).EnsureAsync(Ct);
+        log.Warnings.ShouldContain(m => m.Contains("Could not add the tag index", StringComparison.Ordinal)
+                                        && m.Contains(QuestDbTables.AddTagIndex(conn.SampleTable), StringComparison.Ordinal));
+    }
+
+    /// <summary>Captures the rendered Warning messages.</summary>
+    private sealed class ListLogger : Microsoft.Extensions.Logging.ILogger
+    {
+        private readonly System.Collections.Concurrent.ConcurrentQueue<string> _warnings = new();
+        public IReadOnlyCollection<string> Warnings => _warnings;
+        public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+        public bool IsEnabled(Microsoft.Extensions.Logging.LogLevel logLevel) => true;
+        public void Log<TState>(Microsoft.Extensions.Logging.LogLevel logLevel, Microsoft.Extensions.Logging.EventId eventId,
+            TState state, Exception? exception, Func<TState, Exception?, string> formatter)
+        {
+            if (logLevel == Microsoft.Extensions.Logging.LogLevel.Warning) _warnings.Enqueue(formatter(state, exception));
+        }
     }
 
     [Fact]