Iteration 2 of cycle 0075: the engine primitive r_bootstrap (moving-block
bootstrap over a flat R series, reusing MetricStats/SplitMix64); the CLI
parse_mc_args/McArgs split (synthetic seed-resweep preserved byte-for-byte;
the --strategy stage1-r real-R path reuses iter-1's walkforward_family +
RMetrics.trade_rs); run_mc_r_bootstrap prints one mc_r_bootstrap line. The
mc real-R path accepts only --strategy stage1-r, so a bare --real stays a
usage error (mc_rejects_real_flag_with_usage_exit_2 preserved).
refs #139
Brummel
b3505c7609