fix(mqtt): Sparkplug array and unsupported-type metrics are not bindable from the browser (R06:M-5)

The ingestor refuses array metrics and unmapped types, yet DescribeMetric still stated
their binding tuple, so a browse-commit produced a tag stuck at
BadWaitingForInitialData forever. Those leaves now state no address (the commit
refuses them) and say why in the descriptor line.

Refs #744
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

docs/drivers/Mqtt.md

@@ -249,7 +249,10 @@ One subscription (`spBv1.0/{GroupId}/#`) feeds a per-edge-node state machine
   [Structured metrics](#structured-metrics-template--dataset--propertyset).
 - **Unsupported datatypes are skipped with a warning, never guessed**: `PropertySetList`, `Unknown`,
   extension values, and any `Template`/`DataSet` that cannot be flattened honestly. `Int8`→`Int16` and
-  `UInt8`→`UInt16` widen; `*Array` variants map to the element type with the array bit set.
+  `UInt8`→`UInt16` widen; `*Array` variants map to the element type with the array bit set — but
+  **array metrics are not read in v1** (warned once, never fed), so the browse picker offers them, and any
+  metric whose type is unsupported, **without an address**: the browse-commit refuses them rather than
+  committing a tag that waits for initial data forever (R06:M-5).
 - **Ingest state is reset at every session/authoring seam** — a reconnect or a `ReinitializeAsync`
   must not carry a previous session's alias table into a new one.
 

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Browser/MqttBrowseSession.cs

@@ -441,16 +441,25 @@ internal sealed class MqttBrowseSession : IRebirthCapableBrowseSession
         var mapped = metric.DataType?.ToDriverDataType();
         var sparkplugName = metric.DataType?.ToString() ?? nameof(SparkplugDataType.Unknown);
 
+        var isArray = metric.DataType?.IsSparkplugArray() ?? false;
+
         var descriptor = new StringBuilder(metric.BirthType.ToString()).Append(" · ").Append(sparkplugName);
         if (metric.Alias is { } alias) descriptor.Append(" · alias ").Append(alias);
         if (mapped is null) descriptor.Append(" · unsupported in v1 — not bindable");
+        else if (isArray) descriptor.Append(" · array metrics are not read in v1 — not bindable");
+
+        // Unbindable = the ingestor refuses it: an unmapped type, or ANY array variant (SparkplugIngestor
+        // gates on the array bit and never feeds the tag). Such a leaf states NO address, so the
+        // browse-commit refuses it at commit instead of writing a tag that sits at
+        // BadWaitingForInitialData forever (R06:M-5). Labelling it alone was not enough — it still bound.
+        var bindable = mapped is not null && !isArray;
 
         return new AttributeInfo(
             metric.Name,
             mapped?.ToString() ?? sparkplugName,
-            metric.DataType?.IsSparkplugArray() ?? false,
+            isArray,
             descriptor.ToString(),
-            AddressFields: BuildMetricAddressFields(metric.Name, scope));
+            AddressFields: bindable ? BuildMetricAddressFields(metric.Name, scope) : null);
     }
 
     /// <summary>

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Mqtt.Tests/MqttBrowseSessionTests.cs

@@ -779,6 +779,13 @@ public sealed class MqttBrowseSessionTests
             "Plant1/EdgeA::Profile", TestContext.Current.CancellationToken)).ShouldHaveSingleItem();
         a.DriverDataType.ShouldBe(nameof(Core.Abstractions.DriverDataType.Int32));   // element type
         a.IsArray.ShouldBeTrue();
+
+        // R06:M-5: the ingestor refuses array metrics ("not supported in v1"), so the browser must not
+        // offer one as bindable — no stated address means the browse-commit refuses it in words, instead
+        // of committing a tag that sits at BadWaitingForInitialData forever. The scalar control is
+        // SparkplugAttributes_StateTheBindingTuple_SoTheCommitNeverParsesTheNodeId.
+        a.AddressFields.ShouldBeNull();
+        a.SecurityClass.ShouldContain("not bindable");
     }
 
     [Fact]
@@ -796,6 +803,7 @@ public sealed class MqttBrowseSessionTests
         Enum.TryParse<Core.Abstractions.DriverDataType>(a.DriverDataType, ignoreCase: true, out _)
             .ShouldBeFalse();                       // not a guessed type — unmappable, and visibly so
         a.SecurityClass.ShouldContain("unsupported");
+        a.AddressFields.ShouldBeNull();             // R06:M-5 — labelled AND unbindable, not just labelled
     }
 
     [Fact]