test(e2e): use web-first toast assertion in notification tests (review fix)

tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Notifications/NotificationActionTests.cs

@@ -121,11 +121,9 @@ public class NotificationActionTests
             // The retry resolves purely against the central row (no site relay), so a
             // single success toast appears. We assert exactly one toast (the single-toast
             // contract), tolerant of the exact outcome text. The wait is generous (15s)
-            // and the toast auto-dismisses 5s after it appears, so the assertion must
-            // catch it inside that window.
-            var toast = page.Locator(".toast");
-            await Assertions.Expect(toast).ToBeVisibleAsync(new() { Timeout = 15_000 });
-            Assert.Equal(1, await toast.CountAsync());
+            // and the toast auto-dismisses 5s after it appears, so we use a single
+            // web-first retrying assertion to avoid a TOCTOU race with the auto-dismiss.
+            await Assertions.Expect(page.Locator(".toast")).ToHaveCountAsync(1, new() { Timeout = 15_000 });
         }
         finally
         {
@@ -159,10 +157,9 @@ public class NotificationActionTests
             await deleteButton.ClickAsync();
 
             // The discard moves the central row to Discarded and surfaces a single success
-            // toast. Same single-toast / outcome-tolerant assertion as Retry.
-            var toast = page.Locator(".toast");
-            await Assertions.Expect(toast).ToBeVisibleAsync(new() { Timeout = 15_000 });
-            Assert.Equal(1, await toast.CountAsync());
+            // toast. Same single-toast / outcome-tolerant assertion as Retry: a single
+            // web-first retrying assertion to avoid a TOCTOU race with the auto-dismiss.
+            await Assertions.Expect(page.Locator(".toast")).ToHaveCountAsync(1, new() { Timeout = 15_000 });
         }
         finally
         {