PR #3825 added a shared bootstrap context to capture delegated
child-session retry payloads before the first prompt dispatch, so
empty-history failures could still retry through the fallback chain.
The PR's own regression test failed on clean root bun test after merge
(6828 pass / 1 fail). PR #4044 reverted the merge to keep dev green.
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 targets v4.2.1 once the regression test is stabilized.
Closes BLOCKER-4 (Path B - documentation, reland deferred to v4.2.1)
YeonGyu-Kim
f8d6f2a2ec