MOB-48124: Fix isFirstLevelStep to walk ancestor chain, not just check parent

Root-caused via a diagnostic reporter build with per-hook debug logging
(sandbox only): when a whole-test timeout fires while a test.step() loop
is still running, Playwright can attribute still-executing test.step()
calls to its own teardown fixture (e.g. "Fixture \"context\"") as their
parent, instead of null. isFirstLevelStep() previously treated any
non-null parent as nesting, silently dropping these steps from STEP
granularity even though they were never actually nested under another
test.step(). Now walks the full ancestor chain and only disqualifies a
step if a genuine test.step ancestor is found, ignoring hook/fixture
ancestors. Verified via deterministic reproduction: a step with a
corrupted "Fixture \"context\"" parent is now correctly still reported.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: henrychv

bzt/resources/playwright-custom-reporter/playwright-custom-reporter.js

@@ -203,14 +203,20 @@ class TaurusReporter {
   }
 
   // Only first-level test.step() calls are reported (nested test.step calls are skipped).
-  // Playwright's own category enum reserves 'test.step' exclusively for explicit
-  // test.step() calls, so this already excludes hooks, fixtures, expects and pw:api steps.
+  // "First-level" means no ancestor in the parent chain is itself a test.step. A parent
+  // that is a hook/fixture/pw:api step does not count as nesting - it isn't something the
+  // test author wrote. This matters because Playwright can attribute still-running
+  // test.step() calls to its own teardown fixture (e.g. "Fixture \"context\"") as their
+  // parent when a whole-test timeout races with in-flight user code, which would otherwise
+  // make a genuinely top-level step look nested and get silently dropped.
   isFirstLevelStep(step) {
     if (!step || step.category !== 'test.step') {
       return false;
     }
-    if (step.parent) {
-      return false;
+    for (let current = step.parent; current; current = current.parent) {
+      if (current.category === 'test.step') {
+        return false;
+      }
     }
     return true;
   }