fix(tests): revert to single-phase polling with 3-min interval

The 2-phase approach (Thanos API check + UI traversal) failed because
the oc get --raw query to Thanos Querier doesn't return alert data as
expected in the CI environment.

Revert to the original single-phase UI traversal but with a 3-minute
interval instead of 1-minute. This reduces the number of heavy
findIncidentWithAlert iterations from ~30 to ~10, keeping the Cypress
command log small enough to avoid Chrome OOM (exit code 137).

CI run: https://prow.ci.openshift.org/view/gs/test-platform-results/pr-logs/pull/openshift_monitoring-plugin/860/pull-ci-openshift-monitoring-plugin-main-e2e-incidents/2038898485348012032
Classifications: TEST_BUG (Phase 1 Thanos API query not working in CI)
22/23 tests passed — no OOM confirmed.

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

Author: DavidRajnoha

web/cypress/e2e/incidents/00.coo_incidents_e2e.cy.ts

@@ -42,36 +42,18 @@ describe('BVT: Incidents - e2e', { tags: ['@smoke', '@slow', '@incidents', '@e2e
     incidentsPage.goTo();
     incidentsPage.clearAllFilters();
 
-    const intervalMs = 60_000;
-    const maxMinutes = 30;
-
-    cy.log('1.2 Wait for alert to start firing on cluster');
-    // Phase 1: Poll the Thanos Querier API to check if the alert is actually
-    // firing. This is lightweight — a single cy.exec per iteration with no
-    // Chrome DOM interaction, preventing the OOM (exit code 137) caused by
-    // repeated heavy UI traversals accumulating Cypress command log snapshots.
-    const kubeconfigPath = Cypress.env('KUBECONFIG_PATH');
-    cy.waitUntil(
-      () => cy.exec(
-        `oc get --raw '/api/v1/namespaces/openshift-monitoring/services/thanos-querier:web/proxy/api/v1/rules?type=alert' --kubeconfig ${kubeconfigPath}`,
-        { failOnNonZeroExit: false, timeout: 20000 },
-      ).then((result) => result.code === 0 && result.stdout.includes(currentAlertName)),
-      {
-        interval: 30_000,
-        timeout: 20 * 60_000,
-        errorMsg: `Alert ${currentAlertName} not firing on cluster within 20 minutes`,
-      }
-    );
-
-    cy.log('1.2.1 Wait for incident detection to pick up the firing alert');
-    // Phase 2: Alert is confirmed firing. Wait for incident detection to group
-    // it into an incident. Uses the UI traversal but with fewer iterations
-    // since incident detection typically takes 5-10 minutes after alert fires.
+    cy.log('1.2 Wait for incident with custom alert to appear');
+    // Use a 3-minute interval instead of 1-minute to reduce the number of
+    // heavy UI traversals. Each findIncidentWithAlert call generates hundreds
+    // of Cypress commands (clicking bars, expanding rows, checking text).
+    // With 1-min interval the command log grew unbounded over 30 iterations
+    // causing Chrome OOM (exit code 137). With 3-min interval we get ~10
+    // iterations max, keeping memory within container limits.
     cy.waitUntil(
       () => incidentsPage.findIncidentWithAlert(currentAlertName),
       {
-        interval: 2 * intervalMs,
-        timeout: 15 * intervalMs,
+        interval: 3 * 60_000,
+        timeout: 30 * 60_000,
       }
     );