cost_nodes_for (beside stop_rule_for_regime) is the one CostSpec ->
bound-builder binding — every component fully bound, so the wrapped
param space stays cost-invariant. run_blueprint_member joins the cost
rows into summarize_r (member metrics genuinely net) and stamps the
cost components into the manifest params; CliMemberRunner threads the
doc's cost. The re-run sides re-derive the model from the manifest:
reproduce via cost_specs_from_params (the #233 stop pattern — a costed
family reproduces bit-identically) and persist_campaign_traces binds
the same model so the C1 drift alarm compares like with like.
Hand-computed pin: a constant cost model yields
net_expectancy_r == expectancy_r - cost_per_trade/|entry-stop| on a
synthetic member.
Verified: full workspace suite green, clippy -D warnings clean; in-loop
spec + quality gates passed per task.
refs #234
Brummel
bb1f6c8bdd