feat(ui/deployment): consolidate sites/areas/instances into Topology page

Single /deployment/topology page replaces /deployment/instances (legacy URL
preserved as a secondary @page directive) and the /admin/areas* CRUD pages.
TreeView with Site → Area → Instance, V1–V7 visual guide (bi-building /
bi-diagram-3 / bi-box), always-visible empty containers, search dim, F2
inline area rename, and right-click context menus per node kind (Add Area,
Move to Area…, lifecycle actions, etc.).

Adds AreaService.MoveAreaAsync with cycle prevention, same-site enforcement,
and name-collision check at the new parent. Instance rename intentionally
out of scope — UniqueName is the site-side actor identity, requires its own
design pass.

tests/ScadaLink.CentralUI.PlaywrightTests/NavigationTests.cs

@@ -45,7 +45,7 @@ public class NavigationTests
     }
 
     [Theory]
-    [InlineData("Instances", "/deployment/instances")]
+    [InlineData("Topology", "/deployment/topology")]
     [InlineData("Deployments", "/deployment/deployments")]
     public async Task DeploymentNavLinks_NavigateCorrectly(string linkText, string expectedPath)
     {