fix(ui/admin): always clear _loading in DataConnectionForm.OnInitializedAsync

src/ScadaLink.CentralUI/Components/Pages/Admin/DataConnectionForm.razor

@@ -120,12 +120,12 @@
     private string? _formError;
 
     protected override async Task OnInitializedAsync()
+    {
+        try
         {
             _sites = (await SiteRepository.GetAllSitesAsync()).ToList();
 
             if (Id.HasValue)
-        {
-            try
             {
                 _editingConnection = await SiteRepository.GetDataConnectionByIdAsync(Id.Value);
                 if (_editingConnection != null)
@@ -147,11 +147,6 @@
                     }
                 }
             }
-            catch (Exception ex)
-            {
-                _formError = $"Failed to load connection: {ex.Message}";
-            }
-        }
             else if (SiteId.HasValue)
             {
                 var site = _sites.FirstOrDefault(s => s.Id == SiteId.Value);
@@ -162,9 +157,16 @@
                     _siteLocked = true;
                 }
             }
-
+        }
+        catch (Exception ex)
+        {
+            _formError = $"Failed to load: {ex.Message}";
+        }
+        finally
+        {
             _loading = false;
         }
+    }
 
     private async Task SaveConnection()
     {