refactor(adminui): retire generic DriverEdit.razor

All 9 driver types now have typed pages; DriverEditRouter dispatches
to them directly. Unknown DriverType strings (e.g. legacy rows) render
an explicit error notice instead of falling through to a generic
editor — the failure mode is now visible, not silent.

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

@@ -26,9 +26,22 @@ else if (_existing is null)
         Driver instance <span class="mono">@DriverInstanceId</span> was not found in cluster <span class="mono">@ClusterId</span>.
     </section>
 }
+else if (ResolveComponentType() is { } pageType)
+{
+    <DynamicComponent Type="pageType" Parameters="BuildParameters()" />
+}
 else
 {
-    <DynamicComponent Type="ResolveComponentType()" Parameters="BuildParameters()" />
+    <div class="d-flex justify-content-between align-items-center mb-3">
+        <h4 class="mb-0">Edit driver instance &middot; <span class="mono">@ClusterId</span></h4>
+        <a href="/clusters/@ClusterId/drivers" class="btn btn-outline-secondary btn-sm">Cancel</a>
+    </div>
+    <ClusterNav ClusterId="@ClusterId" ActiveTab="drivers" />
+    <section class="panel notice rise" style="animation-delay:.02s; border-color:var(--alert)">
+        Driver instance <span class="mono">@DriverInstanceId</span> has an unknown <code>DriverType</code> value of
+        <strong><span class="mono">@_existing.DriverType</span></strong>. No editor is registered for this type.
+        Likely causes: the row was written by a newer build, or the type-string was corrupted in the database.
+    </section>
 }
 
 @code {
@@ -60,10 +73,8 @@ else
         _loaded = true;
     }
 
-    private Type ResolveComponentType()
-        => _componentMap.TryGetValue(_existing!.DriverType, out var t)
-            ? t
-            : typeof(ZB.MOM.WW.OtOpcUa.AdminUI.Components.Pages.Clusters.DriverEdit);
+    private Type? ResolveComponentType()
+        => _componentMap.TryGetValue(_existing!.DriverType, out var t) ? t : null;
 
     private IDictionary<string, object> BuildParameters()
         => new Dictionary<string, object>