Brummel
c8c34c72e7
Four tasks, one iteration: (1) the windowed IS-sweep + OOS-run helpers + blueprint_walkforward_family (mirrors the hard-wired Stage1R walkforward arm one substitution deep — loaded blueprint via blueprint_axis_probe); (2) the --axis/--select parse grammar + IO wrapper (persist via put_blueprint + append_family, content-addressed like aura mc) + the .json walkforward dispatch arm; (3) the reproduce_family_in WalkForward branch (persist+reproduce land together); (4) the E2Es (persist shape, reproduce bit-identical, no-axis reject, malformed-safety) + the full clippy/suite gate. Panic-safety: blueprint_sweep_over returns Result<_, BindError> (user --axis fallible); a bad axis → clean in-closure exit 2 (mirrors the hard-wired arm's select_winner handling), never a panic. reduce-mode members carry R-metrics (no raw pip curve) → empty stitched equity, oos_r is the meaningful summary (C10 R-first). Closes the World/C21 milestone's last piece. refs #173