fix(historian): #680 lane B — per-sample Count/Start/End/Delta per Part 13 + forward end-of-data Partial

Count: Good samples only, value-based status (all Bad => generic Bad), 0/Good on an
empty interval inside the tag's data range [first, last] (both directions).
Start/End: the raw first/last sample of any quality (own value, status, timestamp).
Delta: Uncertain only when the interval's first or last sample is not usable.
Forward end-of-data Partial (SDK m_endOfData, earlier edge inclusive) for every
per-sample aggregate but Average (PercentGood/Bad left to lane A).
Backends push down first/last-any-quality columns and fetch the tag's data range
(earliest <= window end, latest >= window start) only when NeedsDataRange.
SDK parity masks for Start/End/Delta/Count removed; new parity datasets.

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

@@ -155,6 +155,30 @@ public sealed class BucketPlan
     public bool DataStartsInside(long index, DateTime? earliestSampleUtc) =>
         earliestSampleUtc is { } e && e.Ticks > LowerTicks(index) && e.Ticks < UpperTicks(index);
 
+    /// <summary>
+    ///     True when the latest stored sample of the tag lies in bucket <paramref name="index"/> (its earlier edge
+    ///     included): the data ends part-way through the interval, so Part 13 §5.3.3.2 / the SDK set the Partial bit on a
+    ///     forward read (#680, the SDK's <c>m_endOfData &gt;= startTime &amp;&amp; m_endOfData &lt; endTime</c>).
+    /// </summary>
+    /// <param name="index">Zero-based ascending bucket index.</param>
+    /// <param name="latestSampleUtc">The tag's latest stored sample (any quality), or null when it has none.</param>
+    /// <returns>Whether the data ends inside the bucket.</returns>
+    public bool DataEndsInside(long index, DateTime? latestSampleUtc) =>
+        latestSampleUtc is { } l && l.Ticks >= LowerTicks(index) && l.Ticks < UpperTicks(index);
+
+    /// <summary>
+    ///     True when bucket <paramref name="index"/> overlaps the tag's data range <c>[earliest, latest]</c> — neither
+    ///     wholly before the first sample nor wholly after the last (the SDK's <c>GetValues</c> null test:
+    ///     <c>start &gt; last || end &lt; first</c> ⇒ no data, both edges inclusive in either direction). An empty bucket
+    ///     inside the range is a Count of 0, not <c>BadNoData</c> (#680, Part 13 §5.4.3.21).
+    /// </summary>
+    /// <param name="index">Zero-based ascending bucket index.</param>
+    /// <param name="earliestSampleUtc">The tag's earliest stored sample (any quality), or null.</param>
+    /// <param name="latestSampleUtc">The tag's latest stored sample (any quality), or null.</param>
+    /// <returns>Whether the bucket is within the data range.</returns>
+    public bool WithinDataRange(long index, DateTime? earliestSampleUtc, DateTime? latestSampleUtc) =>
+        earliestSampleUtc is { } e && latestSampleUtc is { } l && LowerTicks(index) <= l.Ticks && UpperTicks(index) >= e.Ticks;
+
     /// <summary>One snapshot per bucket in result order; missing buckets get <paramref name="empty"/>; descending if reversed.</summary>
     /// <param name="byBucket">Evaluated snapshots of the non-empty buckets, by ascending bucket index.</param>
     /// <param name="empty">Builds the snapshot of a bucket with no row, from its <see cref="BucketTimestamp"/>.</param>