#3811 typed_workflow_passes_test child-sentinel case flakes under full-suite load: f.received.at(-1) reads the compare step's empty payload

integration/typed_workflow_passes_test.ts, test 'a child workflow binds a parent sentinel as a Secret, issues its own sentinel for a deferred vault.get input, and delivers each once', second withFixture block (line 391). With typed passes off the compare step's guard is false text, so compare runs and the writer records an empty object. The test then asserts f.received.at(-1) is the deliver payload, but compare and deliver have no dependency, so under load compare can finish last and the assertion sees an empty object (Actual empty object vs Expected password/note). Seen in 2 of 3 verify-build runs on 2026-10-23 at main 6482ce42b (no TypeScript changes on the branch, load average 11 to 18), including one run with verify-build alone; the file passes 6 of 6 when run alone. Suggested fix: find the deliver payload in f.received (or assert on both entries regardless of order) instead of taking the last one.