test(playwright): DeploymentActionTests load the lazy Topology tree via a shared helper

The Topology page has loaded lazily (bounded instance pages behind 'Load
instances' loaders) since 9ee402bb (2026-09-09); TopologyAreaTests was
updated then but DeploymentActionTests still relied on one Expand-all click
revealing instance rows, so all four facts timed out locating the row. Move
OpenStableTopologyAsync into TopologyPageHelper and use it from both.

tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Deployment/DeploymentActionTests.cs

@@ -199,19 +199,9 @@ public class DeploymentActionTests : IClassFixture<DeploymentFixture>
     /// </summary>
     private static async Task<ILocator> OpenInstanceContextMenuAsync(IPage page, string uniqueName)
     {
-        await page.GotoAsync($"{PlaywrightFixture.BaseUrl}/deployment/topology");
-        await page.WaitForLoadStateAsync(LoadState.NetworkIdle);
-
-        // Stop the 15s live-updates timer from rebuilding the tree under us.
-        var liveToggle = page.Locator("#live-updates");
-        if (await liveToggle.IsCheckedAsync())
-        {
-            await liveToggle.UncheckAsync();
-        }
-
-        // ExpandAll() recurses every branch (site → area → …), so one click reveals
-        // the nested instance row under site-a's zztest area.
-        await page.Locator("button[aria-label='Expand all areas']").ClickAsync();
+        // The tree loads lazily (since the 2026-09-09 low-findings wave): one Expand-all
+        // click no longer reveals instance rows, which sit behind "Load instances" loaders.
+        await TopologyPageHelper.OpenStableTopologyAsync(page);
 
         var row = page.Locator("div.tv-row", new() { HasText = uniqueName });
         await Assertions.Expect(row).ToBeVisibleAsync(new() { Timeout = 15_000 });