feat(manager): stand up DeepDrftManager CMS host (Phase 1 of two-app split)

InteractiveServer only, full AuthBlocks, no WASM. Controllers scaffolded for future
CMS controller migration. CmsStealthRoutingHandler omitted by design (subdomain topology).

DeepDrftManager/Components/Routes.razor

@@ -0,0 +1,19 @@
+<Router AppAssembly="typeof(App).Assembly"
+        AdditionalAssemblies="new[] { typeof(DeepDrftCms._Imports).Assembly, typeof(AuthBlocksWeb._Imports).Assembly }">
+    <Found Context="routeData">
+        <AuthorizeRouteView RouteData="routeData">
+            <NotAuthorized>
+                @{
+                    NavigationManager.NavigateTo($"account/login?returnUrl={Uri.EscapeDataString(NavigationManager.Uri)}", forceLoad: true);
+                }
+            </NotAuthorized>
+        </AuthorizeRouteView>
+        <FocusOnNavigate RouteData="routeData" Selector="h1" />
+    </Found>
+    <NotFound>
+        <PageTitle>Not found</PageTitle>
+        <p role="alert">Sorry, there's nothing at this address.</p>
+    </NotFound>
+</Router>
+
+@inject NavigationManager NavigationManager