The review fork is a full AIAgent, not an auxiliary_client call, and its
routed branch deliberately skips the parent's reasoning_config (the parent's
effort vocabulary may be invalid for the routed provider). It also never read
the per-task key, so an explicit `auxiliary.background_review.reasoning_effort`
was silently ignored and the routed fork ran at the provider default (#94825).
Routed forks now parse the task key through the shared parse_reasoning_effort
(same levels and `none` alias as every other aux task); unset keeps the
provider default, an unknown level warns and falls through. The same-model
path is untouched: it still inherits the parent's reasoning_config verbatim
for prompt-cache parity.
Salvaged from #94832 (liuhao1024), re-applied on the decomposed
_fork_init_kwargs seam.
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>
liuhao1024
47714f9402