reproduce_family_in hardcoded the default StopRule::Vol{3,2.0} at both
the param-space probe and the member re-run, so a family minted under a
non-default vol-stop (campaign risk-regime cell, or wf/mc/generalize
with --stop-length/--stop-k) spuriously reported DIVERGED.
New stop_rule_from_params re-derives StopRule::Vol from the manifest's
stamped stop_length/stop_k, falling back to the defaults when the keys
are absent (pre-stamp members) — the same one-directional widening
point_from_params applies to missing manifest params, mirroring
campaign_run's stop_rule_for_regime None arm. The stop rides outside
the wrapped param space, so point_from_params could never recover it.
Verified: RED test green, full workspace suite green (independent
mini-verify), clippy -D warnings clean.
closes#233
Brummel
fb145f5a15