feat(review,docs-hygiene): wire documentation-existence admission pre-check

plugins/docs-hygiene/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "docs-hygiene",
-  "version": "0.8.0",
+  "version": "0.8.1",
   "description": "Documentation-hygiene toolkit of six skills: compress (flavor-trim markdown with a semantic-diff safety net), audit-noise (classify markdown noise), extract-ssot (deduplicate repeated content into a single source of truth), audit-encapsulation (detect citations into skill-private surfaces), rename-references (sweep stale references after renames), and audit-derivability (classify whether a whole document earns its existence — could a fresh agent re-derive it from the code?).",
   "author": {
     "name": "Melodic Software",

plugins/docs-hygiene/CHANGELOG.md

@@ -1,5 +1,23 @@
 # Changelog — docs-hygiene plugin
 
+## [0.8.1] — 2026-07-21
+
+### Added
+
+- **`audit-noise` gates its five in-page NOISE shapes behind a whole-page
+  existence pre-check** (#505). Before line-level classification, the skill
+  now asks whether a reader with repository search could derive the page's
+  content from the code itself; a FAIL is a deletion candidate (recommend
+  relocate-then-delete, never auto-delete) and skips the in-page tier table.
+  Decisions, domain language, thin navigation, and policy/wiring pages always
+  pass admission. Reuses `/docs-hygiene:audit-derivability`'s rubric by
+  reference for contested calls (optional namespaced skill invocation,
+  degrading to the admission question standalone when unavailable). Ships as
+  a portable-baseline default; a consuming repo's own declared
+  documentation-existence convention overrides it via
+  `/re-anchor:follow-our-standards`'s resolution ladder. Read-only, matching
+  the skill's existing contract.
+
 ## [0.8.0] — 2026-07-20
 
 ### Added

plugins/docs-hygiene/skills/audit-noise/SKILL.md

@@ -17,6 +17,29 @@ Noise findings (sample): !`bash "${CLAUDE_SKILL_DIR}/scripts/detect.sh" 2>/dev/n
 
 Tracked markdown — rules, skill bodies, instruction files (`CLAUDE.md`, `AGENTS.md`), `docs/`, READMEs — accumulates five NOISE shapes distinct from FLAVOR (owned by the sibling `/compress`). Each shape carries a maintenance tax plus a reader-facing tax that compounds across the corpus. This skill is a read-only classifier: it surfaces candidates with treatment guidance; the author hand-applies every edit.
 
+## Existence pre-check (before in-page noise)
+
+Before classifying in-page noise, ask the whole-page admission question first:
+**could a reader with repository search derive this page's content from the
+code itself?** A page failing admission is a deletion candidate — its finding
+recommends relocate-then-delete (salvage anything admissible first), never a
+line-level noise treatment, and never auto-delete (this skill stays
+read-only).
+
+Four categories always pass admission regardless of derivability: decisions,
+domain language, thin navigation, and policy/wiring. For the four-factor
+scoring behind a contested call, reuse `/docs-hygiene:audit-derivability`'s
+rubric by reference — namespaced skill invocation, optional: invoke it when
+available; otherwise apply the admission question above standalone.
+
+**Org override.** This pre-check is a portable-baseline default. When the
+consuming repository declares its own documentation-existence convention,
+resolve and defer to it via `/re-anchor:follow-our-standards`'s resolution
+ladder (repo-declared source → repo's own conventions → this portable
+baseline) instead of the default above.
+
+Only a page that passes admission proceeds to the five in-page NOISE shapes below.
+
 ## Noise shapes and treatments
 
 | Shape | What it looks like | Default tier | Treatment |
@@ -58,7 +81,14 @@ Single action v1; `relocate` and `generalize` actions are deferred until real de
 
 ## Output schema
 
-Per target file:
+Per target file, the existence pre-check verdict precedes the in-page findings:
+
+```text
+<file>: admission PASS
+<file>: admission FAIL — deletion candidate (relocate-then-delete recommended)
+```
+
+A FAIL skips the in-page tier table below; a PASS proceeds to it:
 
 ```text
 <file>: N finding(s) — T1=<n>, T2=<n>, T3=<n>

plugins/review/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "review",
-  "version": "0.14.8",
+  "version": "0.14.9",
   "description": "Code-review toolkit: six read-only reviewer agents (code, security, architecture, doc drift, build/test/lint, CI-log audit) plus two orchestration skills — a single-lens quality gate and a multi-surface review fan-out with severity-ranked, deduplicated findings.",
   "author": {
     "name": "Melodic Software",

plugins/review/CHANGELOG.md

@@ -3,6 +3,25 @@
 All notable changes to the `review` plugin are documented here. Format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); this plugin uses semantic versioning.
 
+## [0.14.9]
+
+### Added
+
+- **`doc-drift-detector` gates classification behind an existence pre-check**
+  (#505). Before judging a page's accuracy, the agent now asks the admission
+  question first — could a reader with repository search derive this content
+  from the code itself? — and routes an admission failure to a new
+  **Deletion-candidate** category (recommend relocate-then-delete, never
+  auto-delete) instead of forcing it into Stale/Missing/Aspirational.
+  Decisions, domain language, thin navigation, and policy/wiring pages always
+  pass admission. The four-factor scoring behind a contested call reuses
+  `/docs-hygiene:audit-derivability`'s rubric by reference (optional
+  namespaced skill invocation, degrading to the admission question standalone
+  when that plugin is unavailable). Ships as a portable-baseline default;
+  a consuming repo's own declared documentation-existence convention overrides
+  it via `/re-anchor:follow-our-standards`'s resolution ladder. Report-only,
+  matching the agent's existing read-only contract.
+
 ## [0.14.8]
 
 ### Changed

plugins/review/agents/doc-drift-detector.md

@@ -39,12 +39,47 @@ Cross-reference the project's instruction surfaces (`CLAUDE.md`, project rules,
 - External URLs — spot-check for 404s, not exhaustively
 - Version numbers hardcoded in docs vs actual versions in config
 
+## Existence pre-check (before accuracy)
+
+Before evaluating a page's accuracy, ask the admission question first: **could
+a reader with repository search derive this content from the code itself?** A
+page that fails admission is drift by construction — its finding is a
+deletion-candidate recommendation, not an accuracy fix, and the page never
+enters the Stale/Missing/Aspirational classification below.
+
+Four categories always pass admission, regardless of how derivable the
+surrounding page reads:
+
+- **Decisions** — a chosen option erases the record of alternatives rejected
+- **Domain language** — ubiquitous-language definitions the code enforces but
+  does not narrate
+- **Thin navigation** — index/wayfinding pages whose value is curation, not
+  restated content
+- **Policy and wiring** — cross-cutting rules and integration seams no single
+  file states
+
+For the four-factor scoring behind a contested admission call, reuse
+`/docs-hygiene:audit-derivability`'s rubric by reference — namespaced skill
+invocation, optional: invoke it when the `docs-hygiene` plugin is available;
+otherwise apply the admission question above standalone, which stands on its
+own for a pass/fail call.
+
+An admission failure recommends **relocate-then-delete** (salvage anything
+admissible first) — this agent is report-only and never deletes.
+
+**Org override.** This pre-check is a portable-baseline default. When the
+consuming repository declares its own documentation-existence convention,
+resolve and defer to it via `/re-anchor:follow-our-standards`'s resolution
+ladder (repo-declared source → repo's own conventions → this portable
+baseline) instead of the default above.
+
 ## Workflow
 
 1. Pick a documentation area to audit (or audit all when invoked without scope)
-2. Read the documentation file
-3. Cross-reference each factual claim against the actual code/config
-4. Report discrepancies with specific `file:line` references
+2. For each candidate page, run the existence pre-check above before anything else
+3. Read the documentation file
+4. Cross-reference each factual claim against the actual code/config
+5. Report discrepancies with specific `file:line` references
 
 ## Output format
 
@@ -54,11 +89,12 @@ Cross-reference the project's instruction surfaces (`CLAUDE.md`, project rules,
 
 Categorize findings:
 
-1. **Stale** — documentation contradicts current code (fix immediately)
-2. **Missing** — code exists that documentation doesn't cover (add docs)
-3. **Aspirational** — documentation describes planned features as if implemented (clarify status)
+1. **Deletion-candidate** — failed the existence pre-check (recommend relocate-then-delete, never auto-delete)
+2. **Stale** — documentation contradicts current code (fix immediately)
+3. **Missing** — code exists that documentation doesn't cover (add docs)
+4. **Aspirational** — documentation describes planned features as if implemented (clarify status)
 
-Severity baseline when the caller needs tiers: `${CLAUDE_PLUGIN_ROOT}/context/severity.md` — Stale maps to IMPORTANT; Missing and Aspirational map to SUGGESTION.
+Severity baseline when the caller needs tiers: `${CLAUDE_PLUGIN_ROOT}/context/severity.md` — Deletion-candidate and Stale map to IMPORTANT; Missing and Aspirational map to SUGGESTION.
 
 You are a subagent and cannot ask the user questions. Flag ambiguities explicitly in your report instead.