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.Security/SecurityOptions.cs

@@ -17,6 +17,18 @@ public class SecurityOptions
     /// </summary>
     public string LdapSearchBase { get; set; } = string.Empty;
 
+    /// <summary>
+    /// Service account DN for LDAP user searches (e.g., "cn=admin,dc=example,dc=com").
+    /// Required for search-then-bind authentication. If empty, direct bind with
+    /// cn={username},{LdapSearchBase} is attempted instead.
+    /// </summary>
+    public string LdapServiceAccountDn { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Service account password for LDAP user searches.
+    /// </summary>
+    public string LdapServiceAccountPassword { get; set; } = string.Empty;
+
     /// <summary>
     /// LDAP attribute that contains the user's display name.
     /// </summary>