Phase 3 PR 27 — Fleet status dashboard page. New /fleet route shows per-node apply state (ClusterNodeGenerationState joined with ClusterNode for the ClusterId) in a sortable table with summary cards for Total / Applied / Stale / Failed node counts. Stale detection: LastSeenAt older than 30s triggers a table-warning row class + yellow count card. Failed rows get table-danger + red card. Badge classes per LastAppliedStatus: Applied=bg-success, Failed=bg-danger, Applying=bg-info, unknown=bg-secondary. Timestamps rendered as relative-age strings ('42s ago', '15m ago', '3h ago', then absolute date for >24h). Error column is truncated to 320px with the full message in a tooltip so the table stays readable on wide fleets. Initial data load on OnInitializedAsync; auto-refresh every 5s via a Timer that calls InvokeAsync(RefreshAsync) — matches the FleetStatusPoller's 5s cadence so the dashboard sees the most recent state without polling ahead of the broadcaster. A Refresh button also kicks a manual reload; _refreshing gate prevents double-runs when the timer fires during an in-flight query. IServiceScopeFactory (matches FleetStatusPoller's pattern) creates a fresh DI scope per refresh so the per-page DbContext can't race the timer with the render thread; no new DI registrations needed. Live SignalR hub push is deliberately deferred to a follow-up PR — the existing FleetStatusHub + NodeStateChangedMessage already works for external JavaScript clients; wiring an in-process Blazor Server consumer adds HubConnectionBuilder plumbing that's worth its own focused change. Sidebar link added to MainLayout between Overview and Clusters. Full Admin.Tests Unit suite 14 pass / 0 fail — unchanged, no tests regressed. Full Admin build clean (0 errors, 0 warnings). Closes the 'no per-driver dashboard' gap from lmx-followups item #7 at the fleet level; per-host (platform/engine/Modbus PLC) granularity still needs a dedicated page that consumes IHostConnectivityProbe.GetHostStatuses from the Server process — that's the live-SignalR follow-up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.OtOpcUa.Admin/Components/Layout/MainLayout.razor

@@ -5,6 +5,7 @@
         <h5 class="mb-4">OtOpcUa Admin</h5>
         <ul class="nav flex-column">
             <li class="nav-item"><a class="nav-link text-light" href="/">Overview</a></li>
+            <li class="nav-item"><a class="nav-link text-light" href="/fleet">Fleet status</a></li>
             <li class="nav-item"><a class="nav-link text-light" href="/clusters">Clusters</a></li>
             <li class="nav-item"><a class="nav-link text-light" href="/reservations">Reservations</a></li>
         </ul>