The first slice of the risk-regime structural axis (spec/plan abab1f1):
- aura-research: a serializable `RiskRegime` closed vocabulary (externally
tagged, sole variant `Vol { length, k }` — a content-addressable mirror of
the shipped two-variant StopRule, so a future Fixed regime is additive), and
an optional top-level `CampaignDoc.risk: Vec<RiskRegime>` that absent-
serializes (the `description` precedent) — content-id parity for every
risk-less document.
- validate_campaign refuses a non-positive regime (length < 1 or k <= 0, NaN
included) via a new `DocFault::BadRegime`; the CLI renders it as prose at the
research_docs seam (register/validate paths).
- The three CLI-seam E2E tests pin that a well-formed risk section passes
`campaign validate` and a bad one is refused with prose (exit 1, no Debug
leak) — the field is reachable at the seam a data author drives, not only in
library units.
Adding the field is compile-breaking at every `CampaignDoc { .. }` literal
(serde default does not cover Rust construction), so this slice also threads
`risk: vec![]` into the sites across aura-cli and aura-campaign — the
field-addition's compile-gate completion the plan should have scoped here. The
BadRegime prose reads `risk[i]: ...` (the implementer's terser wording over the
plan's illustrative string; the spec pinned no exact text). Full workspace
suite green.
refs #210
Brummel
2f9f3571ae