## What changed
- The thread-resume replay tests now use unchecked mock sequencing so
the replay flow can complete before the test asserts.
- They also poll outbound `/responses` request counts and fail
immediately if replay emits an unexpected extra request.
## Why this fixes the flake
- The previous version asserted while the replay machinery was still
mid-flight, so the test was sometimes checking an intermediate state
instead of the completed behavior.
- Strict mock sequencing made that problem worse by forcing the test to
care about exact sub-step timing rather than about the end result.
- Letting replay settle and then asserting on stabilized request counts
makes the test validate the real contract: the replay path finishes and
does not send extra model requests.
## Scope
- Test-only change.