test(#1972): consolidate 94 command/module regression tests into subject suites

Fold 94 issue-named command/module regression files into the canonical test file
that owns each subject-under-test, across 52 existing suites (state, config, frontmatter,
roadmap-parser, capability-registry, shell-command-projection-dispatch, plan-phase-drift-guard,
health-validation, runtime-converters, commands, etc.). Verbatim block-scoped describe
wrappers; 881 subtests conserved 1:1. No new test files.

Host-env pre-check (per B2): the only GSD_WORKSTREAM/GSD_PROJECT-touching destinations
(intel, planning-workspace) clear those vars hermetically, so folded CLI tests are safe.

Regenerates regression-name allowlist (222->162), ratchets file-count allowlist across
8 buckets (validate entry removed after dropping <=2), makes 34 relocated allow-test-rule
exemptions issue-ref-compliant (ADR-456; prunes 34 stale ids). Repoints CONTEXT.md +
ADR-0002/443/1235/3524 test-file references. lint:ci green.

Part of epic #1969. Closes #1972.

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

docs/adr/0002-command-contract-validation-module.md

@@ -19,7 +19,7 @@ The command file contract defines what makes a valid `commands/gsd/*.md`:
 
 Before this ADR, the command contract was enforced inconsistently:
 - `tests/enh-2790-skill-consolidation.test.cjs` checked existence and frontmatter of specific post-consolidation commands
-- `tests/bug-3135-capture-backlog-workflow.test.cjs` checked `execution_context` @-ref resolution (added 2026-05-05)
+- `tests/docs-update.test.cjs` (folds former `bug-3135-capture-backlog-workflow`, consolidation epic #1969) checked `execution_context` @-ref resolution (added 2026-05-05)
 - No test checked `allowed-tools` validity, `name:` convention, or `description:` non-emptiness across all commands simultaneously
 
 This meant any PR touching a command file could break the contract without a single test catching it. The `add-backlog.md` gap (#3135) is a concrete example: the workflow file was missing for the full consolidation cycle before a targeted regression test was written.