… tmpdirs

create-integration.test.ts invoked the real generator against
`showcase/packages/` and `.github/workflows/`, then healed the mutations
in afterEach. Under `fileParallelism: true` that collided with
generate-registry.test.ts (concurrent readdirSync of `showcase/packages/`
observed partial state → ENOENT) and with every suite that restored
workflow YAMLs from git (`.git/index.lock` contention).

Teach `create-integration/index.ts` to honor two env overrides —
`CREATE_INTEGRATION_PACKAGES_DIR` and `CREATE_INTEGRATION_WORKFLOWS_DIR`
— that redirect its writes to any directory. Production behavior
unchanged (defaults resolve to the real paths as before).

Rewrite the test to create a per-suite `os.tmpdir()`-backed root, seed
it with copies of the three real workflow YAMLs so the generator's
regex-based edits still match, and point both env vars there. The test
now never mutates a tracked file — no restorer, no git invocation, no
cross-suite shared state. generate-registry can scan real
`showcase/packages/` concurrently without collisions.

The regression-guard test still exercises the same cleanup semantics,
just against the tmpdir-backed baseline map instead of
`workflowRestorer.snapshotMap`.

…red module

Hoist tmpdir/write/withTmp helpers and FIXTURES_DIR/VALIDATE_PINS_SCRIPT
path constants out of validate-pins.test.ts so the forthcoming split files
can share them without duplication. Behaviour-neutral.

…ategory

Break the 3567-line validate-pins.test.ts into five smaller test files so
each one fits comfortably under vitest's hardcoded 60s birpc onTaskUpdate
RPC window (upstream vitest #6129: DEFAULT_TIMEOUT = 6e4 in the bundled
birpc). pool: 'forks' + fileParallelism: false already gives each file a
fresh 60s RPC budget; splitting ensures no single file is anywhere near
that cliff even when CI is slow.

Split buckets, chosen for logical cohesion and balanced subprocess load:
- validate-pins.parsers.test.ts       - pure parsers (no validateAll, no subprocess)
- validate-pins.validate-all.test.ts  - in-process validateAll + drift detection
- validate-pins.cli.test.ts           - CLI subprocess exit codes
- validate-pins.eacces.test.ts        - chmod/EACCES-routed subprocess tests
- validate-pins.r-scenarios.test.ts   - R29/R33 regression scenarios

Test count is identical pre/post-split (134 tests). Behaviour-neutral
refactor: no test logic changes, only file boundaries + shared helper
imports.

audit.test.ts is 3034 lines / 119 tests and on Node 22 CI its single-file
runtime grew from 36.7s (PR #4071) to 71.4s (PR #4081) — over the hardcoded
60s birpc onTaskUpdate RPC window (vitest #6129). Same cliff that motivated
the validate-pins split earlier in this PR.

Extract makeTmpTree, makeConfig, writePackage, makeExampleDir, anomalyStrings,
and the AUDIT_SCRIPT path constant into audit.shared.ts so the forthcoming
split files can share them without duplication. No behavior change — the
original audit.test.ts still re-declares its own local copies until the
split commit removes them.

Replaces the monolithic audit.test.ts (3034 lines, 119 tests, ~71s single-file
on Node 22 CI) with three scenario-scoped files, each comfortably under the
60s birpc onTaskUpdate RPC window (vitest #6129):

  - audit.unit.test.ts (59 tests, ~40ms local) — readManifest, countFiles,
    EACCES-on-spec-dir, findExamplesSource (all three describes),
    parseArgs, BORN_IN_SHOWCASE, SLUG_TO_EXAMPLES, isProgrammerBug,
    UnreadableDirError, canonicalizeForIsMain, listShowcasePackageSlugs.
  - audit.audit-package.test.ts (44 tests, ~510ms local) — auditPackage
    (main + direct-caller invariants), buildReport (main + scalar summary
    + --strict exit code), parseArgs --strict/--columns, computeExitCode
    --strict semantics.
  - audit.cli.test.ts (16 tests, ~8.2s local) — main() CLI exit codes,
    --columns filtering, module isMain guard. Isolated here so the
    per-file fork window absorbs all the subprocess cost.

Tests moved, not copied — 119 + 0 + 0 = 119 total preserved. Helpers live in
audit.shared.ts (extracted in the previous commit).

Per-file caps hold with generous margin on CI: even the subprocess-heavy
CLI file (the worst case) is ~8s locally vs the 60s budget.

…s in place

Prior reasons for `fileParallelism: false` are resolved:

- Env-var mutation races (VALIDATE_PINS_REPO_ROOT, SHOWCASE_AUDIT_ROOT,
  VALIDATE_PARITY_REPO_ROOT) are moot under `pool: 'forks'` — every file
  already gets its own node process with its own `process.env`.
- `.git/index.lock` races between suites that call `restoreFromGitHead`
  are fixed by the cross-process lock in test-cleanup.ts.
- The create-integration vs generate-registry collision on
  `showcase/packages/` is fixed by the create-integration tmpdir
  isolation.

Under fork-per-file + parallel, each test file also gets a fresh 60s
birpc `onTaskUpdate` budget (vitest #6129), eliminating the cumulative
RPC back-pressure that tripped unit(20.x/22.x/24.x) on #4018/#4068/#4079.

Empirical: local full suite 158s → 12s, 1061/1061 passing across three
consecutive `--skip-nx-cache` runs with zero timeouts, zero ENOENT, zero
index.lock contention.

… refactor

- test-cleanup.ts: `new Error(msg, { cause })` is ES2022; workspace lib is
  ES2020 so the two-arg overload is missing. Replaced with an
  `errorWithCause()` helper that assigns `.cause` after construction.
  Runtime is identical (Node >=16.9); only the TS signature differs.
- test-cleanup.ts: retyped `SAFE_STDIO` as `StdioOptions` (still frozen at
  runtime to keep `test-cleanup.test.ts` freeze assertion green) so
  spreading `SAFE_EXEC_OPTS` into `execFileSync(..., opts)` no longer trips
  the readonly-vs-mutable-array mismatch on `stdio` (fixes the error at
  create-integration.test.ts:132).
- create-integration/index.ts: dropped unused `devCmd` local and unused
  `args` parameter on `generateDemoPage` (+ call site); both were dead code
  introduced during the parallel-isolation refactor.
- validate-pins.parsers.test.ts: annotated all `withTmp((tmp) => ...)`
  callbacks as `(tmp: string)` for robustness under LSP module-resolution
  glitches. Matches the contract in `validate-pins.shared.ts`.

Tests: 1061/1061 pass (`pnpm nx run @copilotkit/showcase-scripts:test`).