Make the World layer's two OOS validation verbs candidate-aware and
R-reporting instead of locked to the SMA sample blueprint:
- aura walkforward --strategy stage1-r --real <SYM>: roll IS->OOS, sweep
the stage1-r grid in-sample, pick by an R metric, run OOS, report
per-window + across-window-pooled OOS R-metrics.
- aura mc --strategy stage1-r --real <SYM>: moving-block bootstrap of the
pooled OOS per-trade R series -> E[R] distribution / CI.
Frictionless Stage-1 R (costs are Stage-2). Bare walkforward/mc paths and
their goldens preserved byte-for-byte. Grounding-check PASS; signed under
/boss (design forks recorded on the reference issue).
refs #139
