test(#1973): consolidate 48 workflow regression tests into workflow-aspect suites

Fold 48 issue-named workflow-markdown regression files into the canonical test
that owns each workflow aspect (execute-phase-*, plan-phase-*, quick-*, discuss-*,
worktree-cleanup, secure-phase, verify, update, settings, etc.), across 32 existing
suites. Verbatim block-scoped describe wrappers; 281 subtests conserved 1:1. No new
test files. Host-env pre-check: only gsd-settings-advanced spawns CLI and it sets no
GSD_WORKSTREAM/GSD_PROJECT value — no leak risk.

Regenerates regression-name allowlist (222->181), ratchets file-count allowlist
(verify 11->10), makes 30 relocated allow-test-rule exemptions issue-ref-compliant
(ADR-456; prunes 30 stale ids). lint:ci green.

Part of epic #1969. Closes #1973.

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

scripts/lint-test-file-count.allowlist.json

@@ -88,7 +88,6 @@
       "files": [
         "bug-2969-verify-reapply-patches.test.cjs",
         "bug-2994-verify-reapply-patches-installed-path.test.cjs",
-        "bug-3381-verify-work-workstream.test.cjs",
         "bug-3657-verify-reapply-patches-pristine-drift.test.cjs",
         "verify-health.test.cjs",
         "verify-mvp-uat.test.cjs",