feat(adminui): F15 Phase B — cluster CRUD + Overview/Redundancy routes

- ClustersList (/clusters) — table view, row-click opens detail
- NewCluster (/clusters/new) — EditForm with DataAnnotations; redundancy
  mode + node-count coupling enforced client-side (None→1, Warm/Hot→2);
  CreatedBy taken from AuthenticationStateProvider
- ClusterOverview (/clusters/{id}) — cluster details + last-deployment
  badge + node list. Per Q3, the legacy 10-tab monolith is split into
  separate routes; this page hosts the Overview "tab" as its primary slot
- ClusterRedundancy (/clusters/{id}/redundancy) — static ServiceLevelBase
  config view; live ServiceLevel comes via RedundancyStateActor DPS topic
  (deferred to its own follow-up once the SignalR bridge lands)

The other 8 v1 cluster tabs (Equipment, UNS, Namespaces, Drivers, Tags,
ACLs, ScriptedAlarms, Scripts, Audit) land in Phase C/D.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/ClusterRedundancy.razor

@@ -0,0 +1,111 @@
+@page "/clusters/{ClusterId}/redundancy"
+@attribute [Microsoft.AspNetCore.Authorization.Authorize]
+@rendermode RenderMode.InteractiveServer
+@using Microsoft.EntityFrameworkCore
+@using ZB.MOM.WW.OtOpcUa.Configuration
+@using ZB.MOM.WW.OtOpcUa.Configuration.Entities
+@inject IDbContextFactory<OtOpcUaConfigDbContext> DbFactory
+
+@if (!_loaded)
+{
+    <p>Loading…</p>
+}
+else if (_cluster is null)
+{
+    <section class="panel notice rise" style="animation-delay:.02s">
+        Cluster <span class="mono">@ClusterId</span> was not found.
+        <a class="ms-2" href="/clusters">Back to list</a>.
+    </section>
+}
+else
+{
+    <div class="d-flex justify-content-between align-items-center mb-3">
+        <div>
+            <h4 class="mb-0">@_cluster.Name &middot; Redundancy</h4>
+            <span class="mono text-muted">@_cluster.ClusterId</span>
+        </div>
+    </div>
+
+    <ul class="nav nav-tabs mb-3">
+        <li class="nav-item"><a class="nav-link" href="/clusters/@ClusterId">Overview</a></li>
+        <li class="nav-item"><a class="nav-link active" href="/clusters/@ClusterId/redundancy">Redundancy</a></li>
+    </ul>
+
+    <section class="panel notice rise" style="animation-delay:.02s">
+        v2 redundancy is computed at runtime by <span class="mono">RedundancyStateActor</span>
+        on each admin node. The values below are the static configuration; the resolved live
+        <span class="mono">ServiceLevel</span> for each peer is broadcast on the
+        <span class="mono">redundancy-state</span> DPS topic and consumed by the OPC UA host's
+        <span class="mono">ServerStatus</span> publisher. See
+        <a href="/docs/v2/Architecture-v2.md">docs/v2/Architecture-v2.md</a>.
+    </section>
+
+    <section class="card-grid rise mt-3" style="animation-delay:.08s">
+        <div class="metric-card">
+            <div class="panel-head">Cluster redundancy</div>
+            <div class="kv"><span class="k">Mode</span><span class="v">@_cluster.RedundancyMode</span></div>
+            <div class="kv"><span class="k">Node count</span><span class="v">@_cluster.NodeCount</span></div>
+        </div>
+    </section>
+
+    <section class="panel rise mt-3" style="animation-delay:.14s">
+        <div class="panel-head">Node service-level configuration</div>
+        @if (_nodes is null || _nodes.Count == 0)
+        {
+            <div style="padding:1rem" class="text-muted">No nodes registered.</div>
+        }
+        else
+        {
+            <div class="table-wrap">
+                <table class="data-table">
+                    <thead>
+                        <tr>
+                            <th>Node ID</th>
+                            <th>ApplicationUri</th>
+                            <th class="num">ServiceLevel base</th>
+                            <th>Notes</th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        @foreach (var n in _nodes)
+                        {
+                            <tr>
+                                <td><span class="mono">@n.NodeId</span></td>
+                                <td><span class="mono small">@n.ApplicationUri</span></td>
+                                <td class="num">@n.ServiceLevelBase</td>
+                                <td class="text-muted small">
+                                    @if (n.ServiceLevelBase >= 200) { <text>Primary preference</text> }
+                                    else if (n.ServiceLevelBase >= 100) { <text>Secondary preference</text> }
+                                    else { <text>Custom</text> }
+                                </td>
+                            </tr>
+                        }
+                    </tbody>
+                </table>
+            </div>
+        }
+    </section>
+}
+
+@code {
+    [Parameter] public string ClusterId { get; set; } = "";
+
+    private bool _loaded;
+    private ServerCluster? _cluster;
+    private List<ClusterNode>? _nodes;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await using var db = await DbFactory.CreateDbContextAsync();
+        _cluster = await db.ServerClusters.AsNoTracking()
+            .FirstOrDefaultAsync(c => c.ClusterId == ClusterId);
+        if (_cluster is not null)
+        {
+            _nodes = await db.ClusterNodes.AsNoTracking()
+                .Where(n => n.ClusterId == ClusterId)
+                .OrderBy(n => n.NodeId)
+                .ToListAsync();
+        }
+        _loaded = true;
+    }
+}