refactor(driver-pages): address post-review follow-ups

- DriverInstanceSpec carries ClusterId from the deployment artifact;
  DriverHostActor threads the real cluster identity into
  DriverInstanceActor instead of the local NodeId. Old pre-PR
  artifacts without a ClusterId field fall back to the NodeId so
  in-flight deployments keep working.
- DriverHostActor.ChildEntry holds the full DriverInstanceSpec
  (was only carrying DriverType + LastConfigJson). Restart respawns
  preserve RowId, Name, Enabled, ClusterId — no placeholder values.
- Drop the unnecessary _faultLock on DriverInstanceActor — every
  read/write site runs inside an Akka message handler which is
  single-threaded per actor instance.
- DriverStatusPanel.DisposeAsync awaits Timer.DisposeAsync so an
  in-flight 5s tick can't invoke StateHasChanged on a component
  whose hub has already been torn down.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Drivers/DriverStatusPanel.razor

@@ -270,10 +270,12 @@
 
     public async ValueTask DisposeAsync()
     {
-        _timer?.Dispose();
+        // Drain the timer first so an in-flight callback can't invoke StateHasChanged on
+        // a component that's already releasing its hub. System.Threading.Timer implements
+        // IAsyncDisposable in .NET 6+; the async dispose awaits any in-flight callback.
+        if (_timer is not null) await _timer.DisposeAsync();
         _opResultClearTimer?.Dispose();
-        if (_hub is not null)
-            await _hub.DisposeAsync();
+        if (_hub is not null) await _hub.DisposeAsync();
     }
 
     // Map DriverState string → chip CSS class using the 4 defined theme variants.

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DeploymentArtifact.cs

@@ -15,7 +15,8 @@ public sealed record DriverInstanceSpec(
     string Name,
     string DriverType,
     bool Enabled,
-    string DriverConfig);
+    string DriverConfig,
+    string? ClusterId = null);
 
 public static class DeploymentArtifact
 {
@@ -66,6 +67,7 @@ public static class DeploymentArtifact
         var type = el.TryGetProperty("DriverType", out var typeEl) ? typeEl.GetString() : null;
         var enabled = !el.TryGetProperty("Enabled", out var enEl) || enEl.GetBoolean();
         var config = el.TryGetProperty("DriverConfig", out var cfgEl) ? cfgEl.GetString() : null;
+        var clusterId = el.TryGetProperty("ClusterId", out var clEl) ? clEl.GetString() : null;
 
         if (string.IsNullOrWhiteSpace(id) || string.IsNullOrWhiteSpace(type)) return null;
 
@@ -75,7 +77,8 @@ public static class DeploymentArtifact
             Name: name ?? id!,
             DriverType: type!,
             Enabled: enabled,
-            DriverConfig: config ?? "{}");
+            DriverConfig: config ?? "{}",
+            ClusterId: clusterId);
     }
 
     /// <summary>

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverHostActor.cs

@@ -55,7 +55,12 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
 
     private readonly Dictionary<string, ChildEntry> _children = new(StringComparer.Ordinal);
 
-    private sealed record ChildEntry(IActorRef Actor, string DriverType, string LastConfigJson, bool Stubbed);
+    private sealed record ChildEntry(IActorRef Actor, DriverInstanceSpec Spec, bool Stubbed)
+    {
+        // Convenience accessors for sites that don't need the full spec.
+        public string DriverType => Spec.DriverType;
+        public string LastConfigJson => Spec.DriverConfig;
+    }
 
     /// <inheritdoc />
     public ITimerScheduler Timers { get; set; } = null!;
@@ -374,7 +379,10 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
         }
 
         IActorRef child;
-        var clusterId = _localNode.Value;
+        // Prefer the real ClusterId from the deployment artifact; fall back to the local node
+        // identity for pre-PR artifacts that don't carry it yet (older deploys persisted before
+        // ClusterId was added to DriverInstanceSpec).
+        var clusterId = !string.IsNullOrEmpty(spec.ClusterId) ? spec.ClusterId : _localNode.Value;
         if (stub)
         {
             child = Context.ActorOf(
@@ -397,7 +405,7 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
             child.Tell(new DriverInstanceActor.InitializeRequested(spec.DriverConfig));
         }
 
-        _children[spec.DriverInstanceId] = new ChildEntry(child, spec.DriverType, spec.DriverConfig, stub);
+        _children[spec.DriverInstanceId] = new ChildEntry(child, spec, stub);
         _log.Info("DriverHost {Node}: spawned {Type} driver {Id} (stub={Stub})",
             _localNode, spec.DriverType, spec.DriverInstanceId, stub);
     }
@@ -406,7 +414,8 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
     {
         if (!_children.TryGetValue(spec.DriverInstanceId, out var entry)) return;
         entry.Actor.Tell(new DriverInstanceActor.ApplyDelta(spec.DriverConfig, CorrelationId.NewId()));
-        _children[spec.DriverInstanceId] = entry with { LastConfigJson = spec.DriverConfig };
+        // Store the full new spec — a delta can change Name, Enabled, ClusterId, etc. in addition to config.
+        _children[spec.DriverInstanceId] = entry with { Spec = spec };
         _log.Debug("DriverHost {Node}: ApplyDelta queued for {Id}", _localNode, spec.DriverInstanceId);
     }
 
@@ -467,14 +476,8 @@ public sealed class DriverHostActor : ReceiveActor, IWithTimers
         Context.Stop(entry.Actor);
         _children.Remove(msg.DriverInstanceId);
 
-        // Respawn using the same spec that was applied during the last reconcile.
-        SpawnChild(new DriverInstanceSpec(
-            DriverInstanceRowId: Guid.Empty,
-            DriverInstanceId: msg.DriverInstanceId,
-            Name: msg.DriverInstanceId,
-            DriverType: entry.DriverType,
-            Enabled: true,
-            DriverConfig: entry.LastConfigJson));
+        // Respawn from the same spec the last reconcile used — preserves RowId, Name, ClusterId.
+        SpawnChild(entry.Spec);
     }
 
     private void HandleReconnectDriver(ReconnectDriver msg)

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverInstanceActor.cs

@@ -72,9 +72,12 @@ public sealed class DriverInstanceActor : ReceiveActor, IWithTimers
     private readonly ILoggingAdapter _log = Context.GetLogger();
     private string? _currentConfigJson;
 
-    /// <summary>Timestamps of recent Faulted-state transitions; used to compute the 5-minute error count.</summary>
+    /// <summary>
+    ///     Timestamps of recent Faulted-state transitions; used to compute the 5-minute error count.
+    ///     No lock needed — every read/write site runs inside an Akka message handler, which is
+    ///     single-threaded per actor instance.
+    /// </summary>
     private readonly Queue<DateTime> _faultTimestamps = new();
-    private readonly object _faultLock = new();
 
     /// <summary>Active subscription handle (null when not subscribed). Lifetime is one-per-actor —
     /// re-subscribe across reconnects is the consumer's responsibility today (subscribe-once
@@ -412,28 +415,19 @@ public sealed class DriverInstanceActor : ReceiveActor, IWithTimers
 
     private static bool IsGoodStatus(uint statusCode) => (statusCode >> 30) == 0;
 
-    /// <summary>
-    ///     Records a transition into a Faulted / error state for the 5-minute sliding counter.
-    ///     Thread-safe: called from actor message-handling (single-threaded) but guard is cheap.
-    /// </summary>
+    /// <summary>Records a transition into a Faulted / error state for the 5-minute sliding counter.</summary>
     private void RecordFault()
     {
-        lock (_faultLock)
-        {
-            _faultTimestamps.Enqueue(DateTime.UtcNow);
-        }
+        _faultTimestamps.Enqueue(DateTime.UtcNow);
     }
 
     /// <summary>Returns how many fault transitions occurred in the last 5 minutes.</summary>
     private int ErrorCount5Min()
     {
         var cutoff = DateTime.UtcNow.AddMinutes(-5);
-        lock (_faultLock)
-        {
-            while (_faultTimestamps.Count > 0 && _faultTimestamps.Peek() < cutoff)
-                _faultTimestamps.Dequeue();
-            return _faultTimestamps.Count;
-        }
+        while (_faultTimestamps.Count > 0 && _faultTimestamps.Peek() < cutoff)
+            _faultTimestamps.Dequeue();
+        return _faultTimestamps.Count;
     }
 
     /// <summary>