Fix FinOps tab server dropdown not updating when servers change (#496)

The FinOps tab's server selector was only populated once during
initialization. Added RefreshServerList() to update the dropdown
(preserving the current selection) whenever servers are added or
removed via the main window's RefreshServerList flow.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: erikdarlingdata

Lite/Controls/FinOpsTab.xaml.cs

@@ -45,6 +45,32 @@ public void Initialize(LocalDataService dataService, ServerManager serverManager
         RefreshData();
     }
 
+    /// <summary>
+    /// Refreshes the server dropdown from the current server list.
+    /// Called when servers are added or removed.
+    /// </summary>
+    public void RefreshServerList()
+    {
+        if (_serverManager == null) return;
+
+        var previousSelection = ServerSelector.SelectedItem as ServerConnection;
+        var servers = _serverManager.GetAllServers();
+        ServerSelector.ItemsSource = servers;
+
+        if (previousSelection != null)
+        {
+            var match = servers.FirstOrDefault(s => s.Id == previousSelection.Id);
+            if (match != null)
+            {
+                ServerSelector.SelectedItem = match;
+                return;
+            }
+        }
+
+        if (servers.Count > 0)
+            ServerSelector.SelectedIndex = 0;
+    }
+
     private void PopulateServerSelector()
     {
         if (_serverManager == null) return;

Lite/MainWindow.xaml.cs

@@ -304,6 +304,9 @@ private void RefreshServerList()
 
         ServerCountText.Text = $"Servers: {servers.Count}";
 
+        // Refresh FinOps server dropdown when server list changes
+        FinOpsContent.RefreshServerList();
+
         // Refresh overview when server list changes
         _ = RefreshOverviewAsync();
     }