feat(adminui): F15.3 closes F15 — live alerts/script-log, CSV import, Monaco editor

Final F15 batch wires up the SignalR-backed live pages, ports the bulk
equipment importer, and progressively enhances the Script source editor
with Monaco.

Message contracts:
- Commons.Messages.Alerts.AlarmTransitionEvent — fires on every alarm
  state transition; published on the `alerts` DPS topic by future
  ScriptedAlarmActor (F9) emits.
- Commons.Messages.Logging.ScriptLogEntry — one log line emitted by a
  hosted script; published on the `script-logs` DPS topic by future
  VirtualTagActor (F8) + ScriptedAlarmActor (F9) emits.
  (Folder named "Logging" to dodge .gitignore's "logs/" rule.)

SignalR plumbing:
- AlertHub gains MethodName + bridge actor (AlertSignalRBridge)
- ScriptLogHub introduced; ScriptLogSignalRBridge follows the same
  DPS-subscribe → IHubContext fan-out pattern as FleetStatusSignalRBridge
- WithOtOpcUaSignalRBridges now spawns all three bridges
- MapOtOpcUaHubs maps /hubs/script-log alongside the existing hubs

Pages:
- /alerts                      live alarm tail, 200-row capacity
- /script-log                  live script-log tail with level + script
                               filter, 500-row capacity
- /clusters/{id}/equipment/import — CSV bulk Equipment add with preview
                                    (Name/MachineCode/UnsLineId/Driver +
                                    optional ZTag/SAPID/Manufacturer/Model;
                                    skips rows whose MachineCode already
                                    exists in the fleet)
- ScriptEdit progressively enhanced with Monaco editor via JSInterop —
  the textarea remains Blazor's source of truth and Monaco syncs into it
  on every keystroke so @bind keeps working; falls back gracefully if
  the CDN is unreachable.

MainLayout nav gains a "Live" section (Deployments, Alerts, Alarms
historian) and a "Scripts" link under Scripting. ClusterEquipment
surfaces the new Import CSV button.

Tally: F15 ships ~42 razor pages + 3 SignalR hubs + 3 bridge actors.
Microsoft.AspNetCore.SignalR.Client added (was already in central PM).

All 104 v2 tests remain green.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Hubs/AlertSignalRBridge.cs

@@ -0,0 +1,46 @@
+using Akka.Actor;
+using Akka.Cluster.Tools.PublishSubscribe;
+using Akka.Event;
+using Microsoft.AspNetCore.SignalR;
+using ZB.MOM.WW.OtOpcUa.Commons.Messages.Alerts;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Hubs;
+
+/// <summary>
+/// Akka actor that subscribes to the <c>alerts</c> DistributedPubSub topic and forwards each
+/// <see cref="AlarmTransitionEvent"/> to every SignalR client connected to <see cref="AlertHub"/>.
+/// Mirrors <c>FleetStatusSignalRBridge</c>'s design — one bridge per admin node, hub fan-out is
+/// per-node, no cluster-singleton needed.
+/// </summary>
+public sealed class AlertSignalRBridge : ReceiveActor
+{
+    public const string TopicName = "alerts";
+
+    private readonly IHubContext<AlertHub> _hub;
+    private readonly ILoggingAdapter _log = Context.GetLogger();
+
+    public static Props Props(IHubContext<AlertHub> hub) =>
+        Akka.Actor.Props.Create(() => new AlertSignalRBridge(hub));
+
+    public AlertSignalRBridge(IHubContext<AlertHub> hub)
+    {
+        _hub = hub;
+        ReceiveAsync<AlarmTransitionEvent>(ForwardAsync);
+        Receive<SubscribeAck>(_ => { /* DPS confirmation */ });
+    }
+
+    protected override void PreStart() =>
+        DistributedPubSub.Get(Context.System).Mediator.Tell(new Subscribe(TopicName, Self));
+
+    private async Task ForwardAsync(AlarmTransitionEvent msg)
+    {
+        try
+        {
+            await _hub.Clients.All.SendAsync(AlertHub.MethodName, msg);
+        }
+        catch (Exception ex)
+        {
+            _log.Warning(ex, "AlertSignalRBridge: SignalR push failed for {AlarmId}", msg.AlarmId);
+        }
+    }
+}