ADR-0126 — C004 softens to at-least-one strength word (contract 0.11.0 → 0.12.0)

Context

C004 (one-strength-word) required exactly one binding word per requirement. The five-project DX stress test (suspec-works #87) measured it as the single most common authoring loop — natural prose writes zero or two, and rephrasing to exactly one was the dominant friction — while no evidence anywhere distinguishes exactly-one from at-least-one on outcomes (the DX interrogation's Q-02: theater candidate until measured). The check's two real functions are distinct: a requirement with zero binding words is unverifiable-as-written (the defect), and a requirement with several is a split candidate (advice, not a defect).

Decision

C004 becomes at-least-one-strength-word, severity unchanged (warning), with two framings:

• Zero binding words — the C004 warning: the requirement binds on nothing; add the one word it binds on.
• More than one — a split-candidate advisory under the same C004 id: several bindings often mean several requirements; split or justify. Advice-framed, never "expected exactly one."

Contract version bumps 0.11.0 → 0.12.0. The check's name stays one-strength-word (the id and name are the stable contract surface; the semantics line is the row's comment).

Consequences

• suspec-cli pins 0.12.0 and reframes the two messages; the drift guard reconciles.
• The kit's spec-check guide row and canon checks.md row reword to match.
• The friction #87 measured drops to zero mechanical rephrasing for the ≥1 case; the bundling signal survives as advice. If a measurement ever shows exactly-one earns its cost, this supersedes cleanly.

Status

Accepted (2026-07-03).