Cycle 0107, anchored on #198 (campaign executor; #196 blueprint on-ramp
rides along). Encodes the twelve decisions recorded on #198: eleven from
the fork triage (2026-07-03) plus the user-decided executor home (a new
library crate, 2026-07-03). Scope: aura-campaign library crate
(MemberRunner seam, execute, gate evaluation, preflight, realization
assembly), std::walk_forward vocabulary correction to machinery-true
fields, engine ListSpace, registry CampaignRunRecord + campaign_runs
store, CLI campaign-run verb + driver, #196 on-ramp verbs.
Boss-signed via grounding-check PASS (17/17 load-bearing assumptions
ratified against currently-green tests). One construction note carried
to the plan: a private Registry::blueprint_path already exists and is
promoted to public rather than duplicated.
refs #198, refs #196
