feat(mtconnect): serve TIME_SERIES observations as variable-length double[] (#627)

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

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectObservationIndex.cs

@@ -49,8 +49,8 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.MTConnect;
 ///     </para>
 ///     <para>
 ///         <b>Shapes this build does not represent</b> are coded <c>BadNotSupported</c> with a null
-///         value rather than approximated: a <c>TIME_SERIES</c> vector (array materialization is
-///         deferred to P1.5) and a <c>DATA_SET</c> / <c>TABLE</c> observation. The latter carries its
+///         value rather than approximated: a non-Float64 array tag and a <c>DATA_SET</c> / <c>TABLE</c>
+///         observation (a Float64 <c>TIME_SERIES</c> vector is served as <c>double[]</c>, #627). The latter carries its
 ///         real content in <c>&lt;Entry key=…&gt;</c> child elements, which reach a text-valued
 ///         observation concatenated with the keys discarded — a two-entry set reads as the single
 ///         token <c>"12"</c> — and because the type inference correctly demotes those
@@ -85,9 +85,12 @@ internal sealed class MTConnectObservationIndex
     /// <summary>The Agent reported a number the authored type cannot represent.</summary>
     private const uint BadOutOfRange = 0x803C0000u;
 
-    /// <summary>The observation's shape is real data this build cannot represent (TIME_SERIES vectors).</summary>
+    /// <summary>The observation's shape is real data this build cannot represent (a DATA_SET/TABLE, or a non-Float64 array tag).</summary>
     private const uint BadNotSupported = 0x803D0000u;
 
+    /// <summary>A TIME_SERIES vector whose element count disagrees with its declared <c>sampleCount</c>.</summary>
+    private const uint BadDecodingError = 0x80070000u;
+
     /// <summary>The Agent reported text that is not a value of the authored type at all.</summary>
     private const uint BadTypeMismatch = 0x80740000u;
 
@@ -268,13 +271,11 @@ internal sealed class MTConnectObservationIndex
 
         _tags.TryGetValue(observation.DataItemId, out var tag);
 
-        // TIME_SERIES vectors arrive as one space-separated string. P1 does not materialize OPC UA
-        // arrays (deferred to P1.5), and the honest answer is "real data I cannot represent" — not a
-        // type mismatch, and emphatically not the first element parsed out and served as Good.
-        // Checked AFTER the sentinel so an unavailable array tag still reports the truthful no-comms.
+        // TIME_SERIES vectors arrive as one whitespace-separated string (#627). Checked AFTER the
+        // sentinel so an unavailable array tag still reports the truthful no-comms.
         if (tag is { IsArray: true })
         {
-            return new DataValueSnapshot(null, BadNotSupported, sourceTimestamp, serverTimestamp);
+            return BuildArraySnapshot(observation, tag, sourceTimestamp, serverTimestamp);
         }
 
         // An unauthored observation has no declared target type; String is the only coercion that
@@ -286,6 +287,40 @@ internal sealed class MTConnectObservationIndex
             : new DataValueSnapshot(null, status, sourceTimestamp, serverTimestamp);
     }
 
+    /// <summary>
+    ///     Parses a <c>TIME_SERIES</c> vector into a <c>double[]</c>. Only <see cref="DriverDataType.Float64"/>
+    ///     arrays are served (the MTConnect TIME_SERIES element type is a floating-point sample); any other
+    ///     authored array type is <c>BadNotSupported</c> rather than an approximation. All-or-nothing: one
+    ///     unparseable or non-finite token, or a count that disagrees with the observation's own
+    ///     <c>sampleCount</c> (or the tag's fixed <c>ArrayDim</c>), makes the whole vector Bad — a partial
+    ///     vector served as Good would be a silently wrong waveform.
+    /// </summary>
+    private static DataValueSnapshot BuildArraySnapshot(
+        MTConnectObservation observation, MTConnectTagDefinition tag, DateTime sourceTimestamp, DateTime serverTimestamp)
+    {
+        DataValueSnapshot Bad(uint status) => new(null, status, sourceTimestamp, serverTimestamp);
+
+        if (tag.DriverDataType != DriverDataType.Float64) return Bad(BadNotSupported);
+
+        var tokens = observation.Value.Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries);
+        var values = new double[tokens.Length];
+        for (var i = 0; i < tokens.Length; i++)
+        {
+            if (string.Equals(tokens[i], UnavailableSentinel, StringComparison.Ordinal)) return Bad(BadNoCommunication);
+
+            if (!double.TryParse(tokens[i], NumberStyles.Float, CultureInfo.InvariantCulture, out values[i]) ||
+                !double.IsFinite(values[i]))
+            {
+                return Bad(BadTypeMismatch);
+            }
+        }
+
+        if (observation.SampleCount is { } declared && declared != values.Length) return Bad(BadDecodingError);
+        if (tag.ArrayDim > 0 && tag.ArrayDim != values.Length) return Bad(BadDecodingError);
+
+        return new DataValueSnapshot(values, Good, sourceTimestamp, serverTimestamp);
+    }
+
     /// <summary>
     ///     Converts the Agent's text to the tag's authored type. Every parse is
     ///     <see cref="CultureInfo.InvariantCulture"/>: MTConnect is an invariant-format wire, and a