Concurrent submissions at the same SHA (one workflow per fold_idx
for the walk-forward G8 gate) would overwrite each other's
eval_summary.json. Adds a /foldN suffix to the output path so the
aggregator can collect 3+ distinct eval_summary.json files from
/feature-cache/alpha-rl-runs/<sha>/fold0,fold1,fold2/.
Single-fold smokes (n_folds=1) still write to /<sha>/fold0/
directly — backwards-compatible for the prior smoke pattern, just
one level deeper than before.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
a3dc61a05a