Core rollback integration tests abort with stack overflow

The following core integration tests abort with SIGABRT because the test thread overflows its stack, rather than reporting a normal assertion failure:

• suite::compact_resume_fork::snapshot_rollback_past_compaction_replays_append_only_history
• suite::compact_resume_fork::snapshot_rollback_followup_turn_trims_context_updates
• suite::rollout_budget::restates_the_current_remainder_after_rollback

Reproduction on the current upstream main checkout:

cargo nextest run -p codex-core -E "test(snapshot_rollback_followup_turn_trims_context_updates)"
cargo nextest run -p codex-core -E "test(restates_the_current_remainder_after_rollback)"

Both focused tests abort with thread ... has overflowed its stack and retry with the same result. Earlier rollback-test stabilization PRs #22303 and #23391 addressed timing and fixture flakes, but do not prevent this current stack overflow. Please fix the underlying recursion or fixture behavior so the tests complete normally.