The campaign walk_forward stage picked its per-window in-sample winner by
optimize_deflated (argmax) unconditionally, dropping the stage's `select`
field, and both the preflight and the `walkforward` verb's `--real` campaign
sub-branch refused plateau:* with a forward-pointer here (the #210 decision-4
deferral; the synthetic non-`--real` sub-branch has accepted plateau since
#173). Honour plateau selection when no gate precedes the wf stage.
- Preflight: the plateau-in-wf refusal is narrowed to gate-preceded stages.
With no preceding gate the survivors are the full sweep grid, so the
parameter lattice (grid.axis_lens) is exact and optimize_plateau is sound; a
gate filters survivors below the grid, breaking the lattice, so plateau after
any gate stays refused. The refusal is static — document validity must be
data-independent (a gate's filtering depends on the data) — and keeps the
existing "a gated survivor subset has no parameter lattice" message, which now
describes exactly the only case it fires.
- Executor: run_walk_forward_stage threads the per-cell grid.axis_lens and picks
each window's in-sample winner via select_sweep_winner — the same dispatch the
sweep stage uses. (Argmax, deflate=true) is byte-identical to the old
optimize_deflated call, so the argmax grade and content-id pins are unchanged;
the plateau arms read axis_lens and ignore deflate.
- CLI: the walkforward verb threads --select through translate_walkforward /
run_walkforward_sugar (a walkforward-local param, not the shared four-verb
SugarInvocation), mapping the parsed Selection to the research SelectRule via
select_rule_of; the refusal and its select_is_plateau helper are deleted.
Scope is walkforward-only — the mc verb's wf-stage select is untouched.
The plateau:worst grade anchor (stitched_total_pips = -9683776.67) is distinct
from the argmax anchor (-10398606.67), proving the plateau path genuinely
changes winner selection rather than falling back to argmax. A gate-free plateau
process validates clean while a gate-preceded one is refused (a new
campaign-validate e2e). Argmax defaults stay byte-identical.
closes#215
Brummel
94cdbf90cc