fix(adminui): wire Test Connect probes + live panels on admin-only nodes

Both bugs surfaced only on split-role deployments (the MAIN cluster's
admin-only nodes), where the AdminUI runs without the driver role.

- Test Connect returned "No probe registered" for every driver: the
  IDriverProbe set was registered only under the driver role, but the
  admin-operations singleton that consumes it is pinned to admin. Extract
  AddOtOpcUaDriverProbes() (idempotent via TryAddEnumerable) and call it
  in the hasAdmin path too.

- Live driver-status/alerts/script-log panels showed "SignalR error:
  Connection refused": these Blazor Server components opened a HubConnection
  to their own hub via the browser's public URL, which server-side code
  can't reach behind Traefik (host :9200 -> container :9000). Read the
  in-process source directly instead -- DriverStatus via
  IDriverStatusSnapshotStore.SnapshotChanged, Alerts/ScriptLog via a new
  IInProcessBroadcaster<T>. Fleet status was unaffected (reads DB/ActorSystem).

Adds unit tests for probe registration, the snapshot-store event, and the
broadcaster.

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/DriverStatusSnapshotStoreTests.cs

@@ -0,0 +1,59 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.AdminUI.Hubs;
+using ZB.MOM.WW.OtOpcUa.Commons.Messages.Drivers;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests;
+
+/// <summary>
+///     Covers the in-process push contract the Blazor Server <c>DriverStatusPanel</c> relies on:
+///     <see cref="IDriverStatusSnapshotStore.SnapshotChanged"/> fires on every
+///     <see cref="IDriverStatusSnapshotStore.Upsert"/>, and <c>TryGet</c> returns the latest.
+///     The panel subscribes to this store directly instead of opening a self-targeted SignalR
+///     connection (which a server-side component can't reach behind a reverse proxy).
+/// </summary>
+public sealed class DriverStatusSnapshotStoreTests
+{
+    private static DriverHealthChanged Snap(string instance, string state = "Healthy") =>
+        new("MAIN", instance, state, null, null, 0, new DateTime(2026, 5, 29, 0, 0, 0, DateTimeKind.Utc));
+
+    [Fact]
+    public void Upsert_raises_SnapshotChanged_with_the_stored_snapshot()
+    {
+        var store = new InMemoryDriverStatusSnapshotStore();
+        var received = new List<DriverHealthChanged>();
+        store.SnapshotChanged += received.Add;
+
+        var snap = Snap("drv-1", "Faulted");
+        store.Upsert(snap);
+
+        received.Count.ShouldBe(1);
+        received[0].ShouldBeSameAs(snap);
+    }
+
+    [Fact]
+    public void Upsert_then_TryGet_returns_the_latest_snapshot()
+    {
+        var store = new InMemoryDriverStatusSnapshotStore();
+        store.Upsert(Snap("drv-1", "Healthy"));
+        store.Upsert(Snap("drv-1", "Degraded"));
+
+        store.TryGet("drv-1", out var latest).ShouldBeTrue();
+        latest.State.ShouldBe("Degraded");
+    }
+
+    [Fact]
+    public void Unsubscribed_handler_stops_receiving_after_removal()
+    {
+        var store = new InMemoryDriverStatusSnapshotStore();
+        var count = 0;
+        void Handler(DriverHealthChanged _) => count++;
+
+        store.SnapshotChanged += Handler;
+        store.Upsert(Snap("drv-1"));
+        store.SnapshotChanged -= Handler;
+        store.Upsert(Snap("drv-1"));
+
+        count.ShouldBe(1);
+    }
+}

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/InProcessBroadcasterTests.cs

@@ -0,0 +1,51 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.AdminUI.Hubs;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests;
+
+/// <summary>
+///     Covers the in-process fan-out the Blazor Server Alerts / Script log pages rely on:
+///     <see cref="IInProcessBroadcaster{T}.Publish"/> raises <c>Received</c> for every current
+///     subscriber, and unsubscribing stops delivery. These pages read this broadcaster directly
+///     instead of opening a self-targeted SignalR connection (unreachable behind a reverse proxy).
+/// </summary>
+public sealed class InProcessBroadcasterTests
+{
+    [Fact]
+    public void Publish_raises_Received_for_all_current_subscribers()
+    {
+        var broadcaster = new InProcessBroadcaster<string>();
+        var a = new List<string>();
+        var b = new List<string>();
+        broadcaster.Received += a.Add;
+        broadcaster.Received += b.Add;
+
+        broadcaster.Publish("evt-1");
+
+        a.ShouldBe(["evt-1"]);
+        b.ShouldBe(["evt-1"]);
+    }
+
+    [Fact]
+    public void Unsubscribed_handler_stops_receiving()
+    {
+        var broadcaster = new InProcessBroadcaster<string>();
+        var received = new List<string>();
+        void Handler(string s) => received.Add(s);
+
+        broadcaster.Received += Handler;
+        broadcaster.Publish("first");
+        broadcaster.Received -= Handler;
+        broadcaster.Publish("second");
+
+        received.ShouldBe(["first"]);
+    }
+
+    [Fact]
+    public void Publish_with_no_subscribers_does_not_throw()
+    {
+        var broadcaster = new InProcessBroadcaster<int>();
+        Should.NotThrow(() => broadcaster.Publish(42));
+    }
+}

tests/Server/ZB.MOM.WW.OtOpcUa.Host.IntegrationTests/DriverProbeRegistrationTests.cs

@@ -0,0 +1,69 @@
+using Microsoft.Extensions.DependencyInjection;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Host.Drivers;
+
+namespace ZB.MOM.WW.OtOpcUa.Host.IntegrationTests;
+
+/// <summary>
+///     Guards the Test Connect wiring contract: every driver type editable in the AdminUI must have
+///     a registered <see cref="IDriverProbe"/>, resolvable from the same DI container that hosts the
+///     <c>admin-operations</c> cluster singleton. The singleton is role-pinned to <c>admin</c>, so on
+///     a split-role deployment (the MAIN cluster's admin-only nodes) the probes must be wired by the
+///     admin path — not only the driver path — or every Test Connect button returns
+///     "No probe registered for driver type X".
+/// </summary>
+public sealed class DriverProbeRegistrationTests
+{
+    // The canonical "all drivers" set — one entry per AdminUI typed driver page's DriverTypeKey.
+    // Keep in sync with the DriverTypeKey constants in
+    // src/Server/.../Components/Pages/Clusters/Drivers/*DriverPage.razor.
+    private static readonly string[] AdminUiDriverTypeKeys =
+    [
+        "ModbusTcp",
+        "AbCip",
+        "AbLegacy",
+        "S7",
+        "TwinCat",               // page key; probe reports "TwinCAT" — must resolve case-insensitively
+        "Focas",                 // page key; probe reports "FOCAS"  — must resolve case-insensitively
+        "OpcUaClient",
+        "GalaxyMxGateway",
+        "Historian.Wonderware",
+    ];
+
+    [Fact]
+    public void AddOtOpcUaDriverProbes_registers_a_probe_for_every_AdminUI_driver_type()
+    {
+        var services = new ServiceCollection();
+        services.AddOtOpcUaDriverProbes();
+
+        using var sp = services.BuildServiceProvider();
+        var probes = sp.GetServices<IDriverProbe>().ToList();
+
+        // No duplicate DriverType — AdminOperationsActor builds a dictionary keyed by DriverType
+        // (case-insensitive) and would throw on a duplicate key, crashing the singleton.
+        var byType = probes.ToDictionary(p => p.DriverType, StringComparer.OrdinalIgnoreCase);
+
+        foreach (var key in AdminUiDriverTypeKeys)
+            byType.ContainsKey(key).ShouldBeTrue($"No IDriverProbe registered for AdminUI driver type '{key}'.");
+    }
+
+    [Fact]
+    public void AddOtOpcUaDriverProbes_is_idempotent()
+    {
+        // A fused admin,driver node calls the registration from both the driver-factory path and the
+        // admin path. TryAddEnumerable must de-dup so the probe set stays unique (else the actor's
+        // ToDictionary throws).
+        var services = new ServiceCollection();
+        services.AddOtOpcUaDriverProbes();
+        services.AddOtOpcUaDriverProbes();
+
+        using var sp = services.BuildServiceProvider();
+        var probes = sp.GetServices<IDriverProbe>().ToList();
+
+        var distinctTypes = probes.Select(p => p.DriverType).Distinct(StringComparer.OrdinalIgnoreCase).Count();
+        probes.Count.ShouldBe(distinctTypes, "Duplicate IDriverProbe registrations — TryAddEnumerable should de-dup.");
+        distinctTypes.ShouldBe(AdminUiDriverTypeKeys.Length);
+    }
+}