test(#1975): consolidate 51 CLI + scripts-tooling regression tests into module suites

Fold 51 issue-named CLI black-box + scripts-tooling regression files into their
canonical module suites (runtime-launcher-parity, worktree-safety, install-*, managed-hooks,
read-guard, capability-registry, etc.), plus a NEW slash-command-namespace.test.cjs grouping
the 4 slash/colon-namespace-leak invariant suites that had no canonical owner. Verbatim
block-scoped describe wrappers; 427 subtests conserved 1:1.

Host-env pre-check (per B2): no CLI-receiving host sets a redirecting GSD_WORKSTREAM/GSD_PROJECT
value. One folded suite (bug-3668 runtime resolver) creates an extension-less PATH gsd-tools
stub + bash -c; co-locating it with the host's chmodSync tripped local/no-unguarded-nonportable-exec,
so it's now Windows-guarded (skip on win32) matching the host suite's own bash -c guard.

Regenerates regression-name allowlist (222->182), ratchets file-count allowlist (graphify 7->6,
docs entry removed), makes 26 relocated allow-test-rule exemptions issue-ref-compliant (ADR-456;
prunes stale ids). Repoints 13 tests/ references across CONTEXT.md, COMMANDS.md/FEATURES.md
(EN + ja/ko/pt/zh) and ADR-0002. lint:ci green.

Part of epic #1969. Closes #1975.

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

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

@@ -12,7 +12,6 @@
     },
     "graphify": {
       "files": [
-        "bug-622-graphify-optional-graph-html.test.cjs",
         "graphify-auto-update.slow.test.cjs",
         "graphify-command-cutover.test.cjs",
         "graphify-query.test.cjs",
@@ -113,14 +112,6 @@
       ],
       "issue": "#1165"
     },
-    "docs": {
-      "files": [
-        "docs-parity-live-registry.test.cjs",
-        "docs-update.test.cjs",
-        "fix-1464-docs-manifest-validation.test.cjs"
-      ],
-      "issue": "1496"
-    },
     "host-integration": {
       "files": [
         "host-integration.test.cjs",