feat(adminui): F15 Phase A — shell + auth + fleet + hosts pages

Implements Phase A of the F15 rebuild plan: minimum-viable Admin surface
with a working sign-in path and a fleet-state landing page. Decisions Q1–Q5
of docs/v2/AdminUI-rebuild-plan.md were taken as recommended.

- App.razor (moved into AdminUI library from the Host stub; vendored
  Bootstrap from RCL wwwroot — no public CDN, air-gap safe)
- Routes.razor (AuthorizeRouteView enforces page-level [Authorize])
- RedirectToLogin.razor (preserves returnUrl through the auth hop)
- Login.razor (static SSR, posts to /auth/login; Q5 wording about
  generic-vs-specific LDAP errors)
- Account.razor (identity + fleet roles + raw LDAP groups; Q4 — no
  per-cluster grants; fleet-wide LDAP-group → role mapping only)
- Fleet.razor (per-node deployment status: reads NodeDeploymentState
  + unions with IClusterRoleInfo.MembersWithRole("driver") so freshly-
  joined nodes appear as "waiting"; 10s auto-refresh)
- Hosts.razor (Akka cluster topology: members, status, roles, role-
  leader; 5s auto-refresh)

Host's stub App.razor deleted; Program.cs now points at
AdminUI.Components.App via an added using.

All 104 v2 tests remain green.

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

@@ -0,0 +1,180 @@
+@page "/fleet"
+@* Per-node deployment status. v2 reads NodeDeploymentState (the per-(node, deployment) apply
+   progress row owned by each DriverHostActor) and projects the most-recent row per node. The
+   Akka cluster topology comes from IClusterRoleInfo so we can show nodes that haven't applied
+   anything yet alongside nodes that have. *@
+@attribute [Microsoft.AspNetCore.Authorization.Authorize]
+@rendermode RenderMode.InteractiveServer
+@using Microsoft.EntityFrameworkCore
+@using ZB.MOM.WW.OtOpcUa.Commons.Interfaces
+@using ZB.MOM.WW.OtOpcUa.Configuration
+@using ZB.MOM.WW.OtOpcUa.Configuration.Entities
+@using ZB.MOM.WW.OtOpcUa.Configuration.Enums
+@inject IClusterRoleInfo Cluster
+@inject IDbContextFactory<OtOpcUaConfigDbContext> DbFactory
+@implements IDisposable
+
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h4 class="mb-0">Fleet status</h4>
+</div>
+
+<div class="d-flex align-items-center mb-3 gap-2">
+    <button class="btn btn-sm btn-outline-primary" @onclick="RefreshAsync" disabled="@_refreshing">
+        @if (_refreshing) { <span class="spinner-border spinner-border-sm me-1" /> }
+        Refresh
+    </button>
+    <span class="text-muted small">
+        Auto-refresh every @RefreshIntervalSeconds s. Last updated: @(_lastRefreshUtc?.ToString("HH:mm:ss 'UTC'") ?? "—")
+    </span>
+</div>
+
+@if (_rows is null)
+{
+    <p>Loading…</p>
+}
+else if (_rows.Count == 0)
+{
+    <section class="panel notice rise" style="animation-delay:.02s">
+        No driver-role nodes are currently Up in the Akka cluster, and no NodeDeploymentState
+        rows have been recorded yet. Either no driver nodes have joined or the cluster is still
+        forming.
+    </section>
+}
+else
+{
+    <section class="agg-grid rise" style="animation-delay:.02s">
+        <div class="agg-card">
+            <div class="agg-label">Nodes</div>
+            <div class="agg-value numeric">@_rows.Count</div>
+        </div>
+        <div class="agg-card">
+            <div class="agg-label">Applied</div>
+            <div class="agg-value numeric">@_rows.Count(r => r.Status == NodeDeploymentStatus.Applied)</div>
+        </div>
+        <div class="agg-card caution">
+            <div class="agg-label">Applying</div>
+            <div class="agg-value numeric">@_rows.Count(r => r.Status == NodeDeploymentStatus.Applying)</div>
+        </div>
+        <div class="agg-card alert">
+            <div class="agg-label">Failed</div>
+            <div class="agg-value numeric">@_rows.Count(r => r.Status == NodeDeploymentStatus.Failed)</div>
+        </div>
+    </section>
+
+    <section class="panel rise" style="animation-delay:.08s">
+        <div class="panel-head">Nodes</div>
+        <div class="table-wrap">
+            <table class="data-table">
+                <thead>
+                    <tr>
+                        <th>Node</th>
+                        <th>Roles</th>
+                        <th>Status</th>
+                        <th>Applied at</th>
+                        <th>Started at</th>
+                        <th>Failure reason</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    @foreach (var r in _rows)
+                    {
+                        <tr>
+                            <td><span class="mono">@r.NodeId</span></td>
+                            <td>
+                                @foreach (var role in r.Roles)
+                                {
+                                    <span class="chip chip-idle me-1">@role</span>
+                                }
+                            </td>
+                            <td><span class="chip @StatusChipClass(r.Status)">@StatusLabel(r.Status)</span></td>
+                            <td>@(r.AppliedAtUtc?.ToString("u") ?? "—")</td>
+                            <td>@(r.StartedAtUtc?.ToString("u") ?? "—")</td>
+                            <td>@(r.FailureReason ?? "")</td>
+                        </tr>
+                    }
+                </tbody>
+            </table>
+        </div>
+    </section>
+}
+
+@code {
+    private const int RefreshIntervalSeconds = 10;
+
+    private List<NodeRow>? _rows;
+    private bool _refreshing;
+    private DateTime? _lastRefreshUtc;
+    private Timer? _timer;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await LoadAsync();
+        _timer = new Timer(_ => _ = InvokeAsync(LoadAsync), null,
+            TimeSpan.FromSeconds(RefreshIntervalSeconds),
+            TimeSpan.FromSeconds(RefreshIntervalSeconds));
+    }
+
+    private async Task RefreshAsync() => await LoadAsync();
+
+    private async Task LoadAsync()
+    {
+        _refreshing = true;
+        StateHasChanged();
+        try
+        {
+            await using var db = await DbFactory.CreateDbContextAsync();
+            // Project the most-recent NodeDeploymentState per node — that's the row the
+            // DriverHostActor most recently touched, regardless of which deployment it was for.
+            var states = await db.NodeDeploymentStates.AsNoTracking()
+                .GroupBy(s => s.NodeId)
+                .Select(g => g.OrderByDescending(s => s.StartedAtUtc).First())
+                .ToListAsync();
+            var byNode = states.ToDictionary(s => s.NodeId);
+
+            // Union with current Akka driver members so a freshly-joined node that has no
+            // NodeDeploymentState row yet still appears as "waiting".
+            var akkaDrivers = Cluster.MembersWithRole("driver")
+                .Select(n => n.Value).ToHashSet(StringComparer.OrdinalIgnoreCase);
+            var allNodes = byNode.Keys.Union(akkaDrivers, StringComparer.OrdinalIgnoreCase)
+                .OrderBy(s => s, StringComparer.OrdinalIgnoreCase).ToList();
+
+            _rows = allNodes.Select(nodeId =>
+            {
+                byNode.TryGetValue(nodeId, out var state);
+                return new NodeRow(
+                    NodeId: nodeId,
+                    Roles: akkaDrivers.Contains(nodeId) ? new[] { "driver" } : Array.Empty<string>(),
+                    Status: state?.Status,
+                    StartedAtUtc: state?.StartedAtUtc,
+                    AppliedAtUtc: state?.AppliedAtUtc,
+                    FailureReason: state?.FailureReason);
+            }).ToList();
+            _lastRefreshUtc = DateTime.UtcNow;
+        }
+        finally
+        {
+            _refreshing = false;
+            StateHasChanged();
+        }
+    }
+
+    private static string StatusChipClass(NodeDeploymentStatus? status) => status switch
+    {
+        NodeDeploymentStatus.Applied => "chip-ok",
+        NodeDeploymentStatus.Applying => "chip-caution",
+        NodeDeploymentStatus.Failed => "chip-alert",
+        _ => "chip-idle",
+    };
+
+    private static string StatusLabel(NodeDeploymentStatus? status) => status?.ToString() ?? "waiting";
+
+    public void Dispose() => _timer?.Dispose();
+
+    private sealed record NodeRow(
+        string NodeId,
+        IReadOnlyCollection<string> Roles,
+        NodeDeploymentStatus? Status,
+        DateTime? StartedAtUtc,
+        DateTime? AppliedAtUtc,
+        string? FailureReason);
+}