Fix auth, Bootstrap, Blazor nav, LDAP, and deployment pipeline for working Central UI

Bootstrap served locally with absolute paths and <base href="/">.
LDAP auth uses search-then-bind with service account for GLAuth compatibility.
CookieAuthenticationStateProvider reads HttpContext.User instead of parsing JWT.
Login/logout forms opt out of Blazor enhanced nav (data-enhance="false").
Nav links use absolute paths; seed data includes Design/Deployment group mappings.
DataConnections page loads all connections (not just site-assigned).
Site appsettings configured for Test Plant A; Site registers with Central on startup.
DeploymentService resolves string site identifier for Akka routing.
Instances page gains Create Instance form.

src/ScadaLink.Host/Program.cs

@@ -152,6 +152,13 @@ try
             services.AddExternalSystemGateway();
             services.AddNotificationService();
 
+            // Configuration database (read-only access for external system definitions, notification lists)
+            var configDbConnectionString = context.Configuration["ScadaLink:Database:ConfigurationDb"];
+            if (!string.IsNullOrWhiteSpace(configDbConnectionString))
+            {
+                services.AddConfigurationDatabase(configDbConnectionString);
+            }
+
             // Site-only components — AddSiteRuntime registers SiteStorageService with SQLite path
             var siteDbPath = context.Configuration["ScadaLink:Database:SiteDbPath"] ?? "site.db";
             services.AddSiteRuntime($"Data Source={siteDbPath}");