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.CentralUI/Components/Pages/Admin/DataConnections.razor

@@ -199,17 +199,15 @@
         try
         {
             _sites = (await SiteRepository.GetAllSitesAsync()).ToList();
+            _connections = (await SiteRepository.GetAllDataConnectionsAsync()).ToList();
 
-            // Load all connections by iterating all sites and collecting unique connections
-            var allConnections = new Dictionary<int, DataConnection>();
+            // Load site assignments for each connection
             _connectionSites.Clear();
-
             foreach (var site in _sites)
             {
                 var siteConns = await SiteRepository.GetDataConnectionsBySiteIdAsync(site.Id);
                 foreach (var conn in siteConns)
                 {
-                    allConnections[conn.Id] = conn;
                     if (!_connectionSites.ContainsKey(conn.Id))
                         _connectionSites[conn.Id] = new List<SiteDataConnectionAssignment>();
 
@@ -218,8 +216,6 @@
                         _connectionSites[conn.Id].Add(assignment);
                 }
             }
-
-            _connections = allConnections.Values.OrderBy(c => c.Name).ToList();
         }
         catch (Exception ex)
         {