test(#1971): consolidate 48 gsd-tools CLI regression tests into subcommand suites

Fold 48 issue-named gsd-tools CLI regression files into the canonical test file
that owns each subcommand subject (state, roadmap, phase, milestone, audit, config,
router/dispatch, stats, verify, health, etc.), preserving every assertion and its
origin issue number as provenance (block-scoped describe wrappers, 299 subtests
conserved 1:1). No monolithic gsd-tools.test.cjs created — routes into 18 existing
per-subject suites.

Removes 48 tests/ files. Regenerates regression-name allowlist (271->231), ratchets
the file-count allowlist across 6 buckets (audit/milestone/phase/roadmap/state/verify),
and makes 10 relocated allow-test-rule exemptions issue-ref-compliant (ADR-456; prunes
10 stale ids). Repoints one CONTEXT.md symptom ref and ADR-3524's parity-test ref.
lint:ci green.

Part of epic #1969. Closes #1971.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/adr/3524-cjs-sdk-hard-seam.md

@@ -137,7 +137,7 @@ parsing from `sdk/dist/query/validate.js`, the same technique used for `escapeRe
 `gen-phase-lifecycle-policy.mjs`. The function is deterministic and pure: no closures over external
 state, no side effects.
 
-**Parity tests:** `tests/6-validate-cjs-drift-regression.test.cjs` — 5 tests (all GREEN after fix,
+**Parity tests:** `tests/health-validation.test.cjs` (folds former `6-validate-cjs-drift-regression`, consolidation epic #1969) — 5 tests (all GREEN after fix,
 all RED on pre-fix `origin/main`). Covers each drift item with concrete fixtures:
 - Drift 1: two milestone archives (v1.0 old, v1.1 active); v1.0 phase absent from ROADMAP.
 - Drift 2: ROADMAP "01A", disk "1A-foo" — padding mismatch.