feat(humanizer): scenario read-test corpus + runner (SC-4) [skip-docs]

Step 9 of v5.1.0 humanizer Wave 4. Adds tests/scenario-read-test.mjs
runner, tests/scenario-read-test.test.mjs wrapper, and 5 scenario
fixtures in tests/scenarios/ that feed deterministic raw findings
through humanizeFinding and assert the humanized
title/description/recommendation match brief-owner-approved regex
patterns encoding the ground-truth what/why/whatNext answers.

Corpus selection (per brief criteria):

- 01-tok-cascade.json - TOK/CPS category (token efficiency)
- 02-cps-volatile.json - TOK/CPS category (cache prefix stability)
- 03-cnf-conflict.json - CNF category (conflicts)
- 04-gap-no-claude-md.json - GAP category (feature gap)
- 05-set-invalid-json.json - SET category, AND its v5.0.0 title +
  description carry tier1 'invalid' (the brief criterion 'one finding
  whose v5.0.0 description uses a forbidden word').

Runner mechanics:

- Loads scenarios matching ^\\d{2}-[a-z0-9-]+\\.json$ in sorted order.
- Calls humanizeFinding(scannerInput) and matches each humanized field
  against its declared pattern (case-insensitive regex).
- Verifies humanizer-added structural fields (userImpactCategory,
  userActionLanguage, relevanceContext) are non-empty strings.
- Per session decision (1a) acceptance is deterministic regex matching
  without a runtime human approval gate.

Wrapper adds 3 tests: scenario-match (binds runner to node --test),
category-coverage (TOK/CPS, CNF, GAP, SET all present), and
tier1-presence (at least one v5.0.0 title or description contains a
tier1 forbidden word).

Tests: 736 to 739 (+3 SC-4 tests). Full suite passes.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/config-audit/tests/scenarios/02-cps-volatile.json

@@ -0,0 +1,29 @@
+{
+  "_meta": {
+    "comment": "Scenario 02: CPS volatile content inside cached prefix. Covers the CPS half of the TOK/CPS category. Tests that the humanizer explains cache-prefix-stability in user-facing language."
+  },
+  "findingId": "CA-CPS-001",
+  "scannerInput": {
+    "id": "CA-CPS-001",
+    "scanner": "CPS",
+    "severity": "medium",
+    "title": "Volatile content inside cached prefix breaks reuse",
+    "description": "Volatile pattern matched at .claude/CLAUDE.md:42 (timestamp). Lines 31-150 form the cache prefix.",
+    "file": ".claude/CLAUDE.md",
+    "line": 42,
+    "evidence": "Pattern: timestamp; window: 31-150",
+    "recommendation": "Move volatile content (timestamps, session state) below line 150 or to a separate file.",
+    "category": null,
+    "autoFixable": false
+  },
+  "expectedHumanized": {
+    "titlePattern": "Content that changes between turns sits in the part Claude tries to reuse",
+    "descriptionPattern": "fresh read every time|slows responses",
+    "recommendationPattern": "Move the changing content|150 lines"
+  },
+  "groundTruth": {
+    "what": "Content that changes between turns is inside the part of the file Claude tries to reuse.",
+    "why": "Claude saves space by reusing the start of your instructions across turns. When that area changes, every turn re-reads the whole start, which slows responses.",
+    "whatNext": "Move the changing content (timestamps, session notes) below the first 150 lines, or out of the file entirely."
+  }
+}