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.Communication/CommunicationOptions.cs

@@ -27,6 +27,12 @@ public class CommunicationOptions
     /// <summary>Timeout for health report acknowledgement (fire-and-forget, but bounded).</summary>
     public TimeSpan HealthReportTimeout { get; set; } = TimeSpan.FromSeconds(10);
 
+    /// <summary>
+    /// Remote actor path for the central communication actor. Used by site nodes to
+    /// register with central on startup (e.g. "akka.tcp://scadalink@central:8081/user/central-communication").
+    /// </summary>
+    public string? CentralActorPath { get; set; }
+
     /// <summary>Akka.Remote transport heartbeat interval.</summary>
     public TimeSpan TransportHeartbeatInterval { get; set; } = TimeSpan.FromSeconds(5);