PR #3825's fac90d69f introduced a shared bootstrap context to fix delegated child-session fallback when the first prompt fails before any session history is persisted. PR #4044 reverted that fix because its own regression test failed on a clean root suite (6828 pass / 1 fail). The bug remains unaddressed in v4.2.0; reland is deferred.
This commit documents the symptom, history, workaround, and tracking issue so users have visibility.
Closes BLOCKER-4 via Path B (documentation).
Refs PR #3825, PR #4044, issue #4059.
PR #3825 introduced a delegated child-session bootstrap to capture first-prompt retry payloads before history is persisted, addressing the empty-history fallback gap. After merge the PR's own regression test failed on clean root bun test (6828 pass / 1 fail), so PR #4044 reverted it. Ship v4.2.0 with the bug documented and a workaround so users have an explicit story for the unfixed delegated child-session early-failure path. Reland will target v4.2.1.
Closes BLOCKER-4 (Path B - reland deferred to v4.2.1)