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/Components/Pages/Alerts.razor

@@ -0,0 +1,126 @@
+@page "/alerts"
+@* Live alarm tail via SignalR. Subscribes to /hubs/alerts and shows the most-recent
+   AlarmTransitionEvent entries. Engine wiring (ScriptedAlarmActor publish on the `alerts`
+   topic) lands with F9; until then the connection stays open and the table is empty. *@
+@attribute [Microsoft.AspNetCore.Authorization.Authorize]
+@rendermode RenderMode.InteractiveServer
+@using Microsoft.AspNetCore.SignalR.Client
+@using ZB.MOM.WW.OtOpcUa.AdminUI.Hubs
+@using ZB.MOM.WW.OtOpcUa.Commons.Messages.Alerts
+@inject NavigationManager Nav
+@implements IAsyncDisposable
+
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Alerts</h4>
+    <div class="d-flex align-items-center gap-2">
+        <span class="conn-pill" data-state="@(_connected ? "connected" : "disconnected")">
+            <span class="dot"></span><span>@(_connected ? "live" : "disconnected")</span>
+        </span>
+        <button class="btn btn-sm btn-outline-secondary" @onclick="ClearAsync">Clear</button>
+    </div>
+</div>
+
+<section class="panel notice rise" style="animation-delay:.02s">
+    Live alarm transitions from the cluster's <span class="mono">alerts</span> DPS topic. Shows
+    the most-recent @Capacity entries since the page opened; reload for a fresh window. Sources:
+    ScriptedAlarmActor, native AB CIP ALMD bridge (F9), Galaxy alarm bridge (future).
+</section>
+
+@if (_rows.Count == 0)
+{
+    <section class="panel notice rise mt-3" style="animation-delay:.08s">
+        No alarms yet. Engine wiring (F9 ScriptedAlarmActor) is pending; once it ships the table
+        below will start populating in real time.
+    </section>
+}
+else
+{
+    <section class="panel rise mt-3" style="animation-delay:.08s">
+        <div class="panel-head">Recent transitions (@_rows.Count)</div>
+        <div class="table-wrap">
+            <table class="data-table">
+                <thead>
+                    <tr>
+                        <th>Time</th>
+                        <th>Alarm</th>
+                        <th>Equipment</th>
+                        <th>Kind</th>
+                        <th class="num">Severity</th>
+                        <th>User</th>
+                        <th>Message</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    @foreach (var e in _rows)
+                    {
+                        <tr>
+                            <td><span class="mono small">@e.TimestampUtc.ToString("HH:mm:ss.fff")</span></td>
+                            <td><span class="mono">@e.AlarmId</span><div class="text-muted small">@e.AlarmName</div></td>
+                            <td><span class="mono small">@e.EquipmentPath</span></td>
+                            <td><span class="chip @KindChipClass(e.TransitionKind)">@e.TransitionKind</span></td>
+                            <td class="num">@e.Severity</td>
+                            <td>@e.User</td>
+                            <td>@e.Message</td>
+                        </tr>
+                    }
+                </tbody>
+            </table>
+        </div>
+    </section>
+}
+
+@code {
+    private const int Capacity = 200;
+
+    private readonly List<AlarmTransitionEvent> _rows = new();
+    private HubConnection? _hub;
+    private bool _connected;
+
+    protected override async Task OnInitializedAsync()
+    {
+        _hub = new HubConnectionBuilder()
+            .WithUrl(Nav.ToAbsoluteUri(AlertHub.Endpoint))
+            .WithAutomaticReconnect()
+            .Build();
+
+        _hub.On<AlarmTransitionEvent>(AlertHub.MethodName, evt =>
+        {
+            _rows.Insert(0, evt);
+            if (_rows.Count > Capacity) _rows.RemoveAt(_rows.Count - 1);
+            InvokeAsync(StateHasChanged);
+        });
+        _hub.Closed += _ => { _connected = false; return InvokeAsync(StateHasChanged); };
+        _hub.Reconnected += _ => { _connected = true; return InvokeAsync(StateHasChanged); };
+
+        try
+        {
+            await _hub.StartAsync();
+            _connected = true;
+        }
+        catch
+        {
+            // Connection failures (admin-only deployment, hub not mapped, etc.) leave the page
+            // showing "disconnected" — operator action: reload or talk to the host operator.
+        }
+    }
+
+    private async Task ClearAsync()
+    {
+        _rows.Clear();
+        await InvokeAsync(StateHasChanged);
+    }
+
+    private static string KindChipClass(string kind) => kind switch
+    {
+        "Activated" => "chip-alert",
+        "Cleared" => "chip-ok",
+        "Acknowledged" or "Confirmed" => "chip-caution",
+        "Shelved" or "Disabled" => "chip-idle",
+        _ => "chip-idle",
+    };
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_hub is not null) await _hub.DisposeAsync();
+    }
+}