Add ISA95 JobControl and ManagedSession regression coverage (#3998)

## Summary

- Adds the official ISA95 JobControl 2.0.0 NodeSet2 as a complete
source-generator regression fixture.
- Extends the lightweight generated-stack test stub with
`NamespaceMetadataState`, required by the complete model.
- Adds a deterministic ManagedSession cancellation regression proving
that a started connect attempt is stopped.

The ManagedSession cleanup implementation and Quickstarts utility
coverage now come from `master`; this PR retains the additional
deterministic cleanup regression.

## ISA95 fixture provenance and integrity

The fixture is byte-for-byte the official file:

- Source:
`OPCFoundation/UA-Nodeset@e0b5d80cfff698f0276393e28df138a7fbc4b541`
- Path: `ISA95-JOBCONTROL/opc.ua.isa95-jobcontrol.nodeset2.xml`
- Git blob: `82f008cd126ade54e5f2c737bcc116621a8c3087`
- SHA-256:
`52327e736beb604c7253a5a5393d1ad525b9ecf35b71fbacb4f429cacb334064`

The fixture test retains the OPC Foundation MIT header and verifies the
2.0.0 model/date, 258 nodes (including 134 variables), representative
late variables, and that every `ns=1` reference target resolves locally.

## Validation

- ManagedSession tests: 17 passing on net10.0; 15 passing and 2
framework-gated skips on net48.
- Quickstarts server utility tests: 3 passing on net10.0 and net48.
- ISA95 generator and fixture integrity regression: 5 passing on
net10.0.

Author: marcschier

tests/Opc.Ua.Client.Tests/Session/ManagedSessionTests.cs

@@ -366,6 +366,48 @@ public async Task DisposeTransitionsToClosedState()
             Assert.That(sm.State, Is.EqualTo(ConnectionState.Closed));
         }
 
+        [Test]
+        public async Task CreateAsyncCancellationStopsStartedConnectAttemptAsync()
+        {
+            ITelemetryContext telemetry = NUnitTelemetryContext.Create();
+            ApplicationConfiguration configuration = CreateClientConfiguration(telemetry);
+            ConfiguredEndpoint endpoint = CreateEndpoint();
+            var gate = new BlockingConnectGate();
+            using var cancellation = new CancellationTokenSource();
+
+            Task<Client.ManagedSession> creation = Client.ManagedSession.CreateAsync(
+                configuration,
+                endpoint,
+                new DefaultSessionFactory(telemetry),
+                connectGate: gate,
+                ct: cancellation.Token);
+
+            Task startedTask = await Task.WhenAny(
+                    gate.Started,
+                    Task.Delay(TimeSpan.FromSeconds(5)))
+                .ConfigureAwait(false);
+            Assert.That(startedTask, Is.SameAs(gate.Started));
+
+            cancellation.Cancel();
+
+            Task completedTask = await Task.WhenAny(
+                    creation,
+                    Task.Delay(TimeSpan.FromSeconds(5)))
+                .ConfigureAwait(false);
+            Assert.That(completedTask, Is.SameAs(creation));
+
+            OperationCanceledException exception =
+                Assert.CatchAsync<OperationCanceledException>(async () =>
+                    await creation.ConfigureAwait(false))!;
+            Assert.That(exception.CancellationToken, Is.EqualTo(cancellation.Token));
+
+            Task stoppedTask = await Task.WhenAny(
+                    gate.Stopped,
+                    Task.Delay(TimeSpan.FromSeconds(5)))
+                .ConfigureAwait(false);
+            Assert.That(stoppedTask, Is.SameAs(gate.Stopped));
+        }
+
         [Test]
         public void CreateAsyncThrowsOnNullConfiguration()
         {
@@ -660,6 +702,35 @@ private static Client.ManagedSession CreateManagedSessionWithInner(
         }
 #pragma warning restore IDE0051, RCS1213
 
+        private sealed class BlockingConnectGate : IClientConnectGate
+        {
+            public Task Started => m_started.Task;
+
+            public Task Stopped => m_stopped.Task;
+
+            public async ValueTask<IDisposable> AcquireAsync(
+                CancellationToken ct = default)
+            {
+                m_started.TrySetResult(null);
+                try
+                {
+                    await Task.Delay(Timeout.Infinite, ct).ConfigureAwait(false);
+                }
+                finally
+                {
+                    m_stopped.TrySetResult(null);
+                }
+
+                throw new InvalidOperationException(
+                    "The blocking connect gate unexpectedly completed without cancellation.");
+            }
+
+            private readonly TaskCompletionSource<object?> m_started =
+                new(TaskCreationOptions.RunContinuationsAsynchronously);
+            private readonly TaskCompletionSource<object?> m_stopped =
+                new(TaskCreationOptions.RunContinuationsAsynchronously);
+        }
+
 #pragma warning disable IDE0051, RCS1213 // Test scaffold kept for ManagedSession construction tests.
         private static ApplicationConfiguration CreateClientConfiguration(
             ITelemetryContext telemetry)

tests/Opc.Ua.SourceGeneration.Core.Tests/CompilerUtils.cs

@@ -768,6 +768,24 @@ public class FolderState : BaseObjectState
                 {
                     public FolderState(NodeState? parent) : base(parent) { }
                 }
+                public class NamespaceMetadataState : BaseObjectState
+                {
+                    public NamespaceMetadataState(NodeState? parent) : base(parent) { }
+                    public void CreateOrReplaceNamespaceUri(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                    public void CreateOrReplaceNamespaceVersion(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                    public void CreateOrReplaceNamespacePublicationDate(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                    public void CreateOrReplaceIsNamespaceSubset(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                    public void CreateOrReplaceStaticNodeIdTypes(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                    public void CreateOrReplaceStaticNumericNodeIdRange(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                    public void CreateOrReplaceStaticStringNodeIdPattern(
+                        ISystemContext context, BaseInstanceState replacement) { }
+                }
                 public class InstrumentDiagnosticAlarmState : BaseEventState
                 {
                     public InstrumentDiagnosticAlarmState(NodeState? parent) : base(parent) { }