Completes the M3 fix for BLOCKER #138. The no-trace stage1-r sweep now folds its
reductions online: `stage1_r_graph(reduce=true)` wires `SeriesReducer` (equity,
exposure -> one summary row each) and `GatedRecorder` (gated on
`closed_this_cycle` -> only the trade rows + the final row), and the folded
consumer rebuilds `RunMetrics` from those compact outputs. Per-member memory drops
from O(cycles) (~2 GiB over ~5.5M one-minute bars) to O(trades), so full-history
multi-member sweeps no longer exhaust RAM+swap. The `r_equity` tap is omitted when
reducing (it is consumed only by the `--trace` persistence path).
`reduce = trace.is_none()`: the `--trace` path and the single `run_stage1_r` keep
the raw recorders + `summarize`/`summarize_r` over full rows — the byte-for-byte
reference. A new CLI-seam test
(`sweep_strategy_stage1_r_folded_no_trace_metrics_equal_raw_trace_metrics`) proves
the folded no-trace sweep reports byte-identical per-member metrics to the raw
`--trace` path.
Verified: cargo test --workspace green (42 suites); cargo clippy --workspace
--all-targets -- -D warnings clean; stage1-r goldens byte-identical.
closes#138
Brummel
eb8653488f