Closes the staleness gap after the 10-commit coverage epic shipped.
Doc sync (item 1 from the user's choice):
- CLAUDE.md Quick Start: adds pnpm coverage:aggregate / coverage:diff
/ mutate to the command listing
- CLAUDE.md: new "Sibling architecture: coverage (ADR-020)" section
after the conformance gate table — captures the 4-layer table +
points at docs/guides/coverage.md + ADR-020 + says agents must run
coverage:diff before reporting complete
- AGENTS.md preamble: now lists coverage as a parallel multi-latency
quality system alongside conformance, with the same gate / latency
framing
- PRD frontmatter: status draft -> shipped + shipped date +
shipping-commits list (all 10 SHAs anchoring the trace)
- PRD findings table: each row gets a Resolution column citing the
commit that closed it; conclusion text updated to past tense
- ADR-020 implementation phasing: rewritten as a status table with
each step linked to the commit that shipped it + Boot-time
assertFeatureConformance explicitly marked Deferred with rationale
- docs/guides/coverage.md: removed "Boot wiring lands in the next
story" line; replaced with the deferral rationale + clarified
that two readers (vitest, coverage:diff) consume the manifest
Sandcastle prompts (item 2 from the user's choice):
- .sandcastle/implementer.prompt.md: new "Coverage gates" section
after the conformance-gates list, requiring `pnpm test --coverage`,
`pnpm coverage:aggregate`, and `pnpm coverage:diff` to all pass
before reporting `complete`. Machine-readable JSON shape of
coverage:diff documented (status / uncovered[] / kind enum), with
explicit instructions on how to interpret each kind. Allowlist
expansion requires justification + test.
- .sandcastle/reviewer.prompt.md: AC coverage relabeled to "AC
coverage (acceptance criteria, not test coverage)" to disambiguate;
new check #7 "Coverage gates (ADR-020)" requiring CI's
Coverage — diff (L1) step green + per-layer thresholds met +
no silent allowlist expansion + manifest band drift detection.
Effect: future agent runs through sandcastle now treat coverage as a
first-class blocking gate, parallel to conformance. PRs no longer
discover coverage failures only via CI; the implementer is required
to check before reporting done, and the reviewer is required to
verify.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Architecture record for the agent-first coverage initiative seeded by
the 2026-05-13 PRD. Captures the durable decisions:
- 4-layer architecture (L0 vitest, L1 diff, L2 aggregate, L3 mutation)
- Manifest-driven coverage band as single source of truth (vitest +
assertFeatureConformance + pnpm coverage:diff all read from it)
- Cover-the-diff (changed lines), not cover-the-new-code
- Committed coverage/summary.json (no SaaS), trend via git log
- Mutation testing scoped to entities + use-cases, on-demand only
- Machine-first output format (JSON stdout, human stderr)
Glossary gets a new "Coverage" section with 7 entries (coverage band,
L0-L3 layers, diff coverage, mutation testing, mutation score,
coverage/summary.json), plus two relationship rows and a flagged
ambiguity for "coverage" qualifiers.
prompt-context.sh hook gets a 9th keyword group — when a prompt
mentions coverage / uncovered / lcov / mutation / stryker, the
relevant ADR + guide path are injected as additional context for
the turn.
This is the documentation layer of the coverage epic. Implementation
(manifest schema, vitest auto-derive, scripts, boot assertion,
mutation tooling) lands in subsequent stories.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
