fix(3426): Codex Windows hooks use .cmd shim to avoid POSIX exec fail (#3768)

* test(#3426): add RED test for Codex Windows hooks .cmd shim requirement

Drive buildCodexHookWindowsShimIR (typed IR) + ensureCodexHooksJsonSessionStart
integration against mocked win32 platform. Counter-tests confirm darwin/linux
paths remain unchanged.

NOTE: Windows wall-clock verification depends on Docker matrix Windows
runners. Local test exercises the generator IR shape only.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(#3426): Codex Windows hooks use .cmd shim to avoid bash.exe POSIX-exec failure

Root cause: Codex on Windows runs hook commands from PowerShell/cmd. The previous
hooks.json command format was `"node.exe" "script.js"`. Codex's hook-dispatch shell
(Git Bash / MSYS) tried to POSIX-exec node.exe (a Windows PE binary) via execvp(),
which fails with ENOEXEC — reported as `bash.exe: cannot execute binary file`.

Fix: `ensureCodexHooksJsonSessionStart` now calls `buildCodexHookWindowsShimIR` on
win32 to write a .cmd shim alongside the .js hook file. cmd.exe executes .cmd files
natively via CreateProcess, bypassing the POSIX exec layer entirely. Non-Windows
paths (darwin, linux) are unchanged: they continue to use the node-runner command.

Also adds `gsd-check-update.cmd` to the codex-hooks-json managed-basename set so
reconcileCodexHooksJsonSessionStart correctly replaces stale node-runner entries on
reinstall.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore(3426): update changeset to reference PR #3768

* fix(3426): fail-loud on Codex Windows shim-write failure instead of silently restoring broken command

Replace the silent fallback to `projectManagedHookCommand` (the old
`node.exe script.js` form) with an explicit warn-and-skip path.

When `atomicWriteFileSync` fails to write the `.cmd` shim, the previous
code silently called `reconcileCodexHooksJsonSessionStart` with the
legacy node-runner command. That command triggers the exact
`bash.exe: cannot execute binary file` POSIX-exec failure that #3426
exists to fix — so a successful-looking install was secretly restoring
the original bug.

New behaviour:
- Emit `console.warn` with the failure reason and a remediation hint,
  matching the `${yellow}⚠${reset}  Skipped …` idiom used at line 9098.
- Return `{ changed: false, wrote: false }` to skip registration for
  this runtime entirely, so the outer caller can surface "NOT installed"
  instead of "installed (but broken)".

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* test(3426): typed-IR assertions on .cmd shim eol/quoting/passthrough + IR extension

Extend `buildCodexHookWindowsShimIR` to expose two new typed fields on
the returned IR object (CONTRIBUTING.md L558-L565 IR-first discipline):

  eol: { cmd: '\r\n' }   — CRLF is canonical for cmd.exe .cmd files
  passthroughArgs: true  — shim forwards all args via %*

Add a new describe block (Step 2b) with three IR-level assertions:

1. `eol.cmd === '\r\n'` — prevents silent EOL regression that could
   break parsing on Windows versions that require CRLF.
2. `invocation.target` is the raw unquoted path (no shell-metachar
   leakage) — quoting happens only at render time.
3. `passthroughArgs === true` — the %* forwarding contract is
   explicitly typed so regressions fail before the text is rendered.

All assertions operate on the typed IR returned by the generator, NOT
on the rendered `.cmd` file content — text-matching is the anti-pattern
CONTRIBUTING.md L522-582 prohibits.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* test(3426): fix Windows CI failures — update hook-command filter patterns

Four test files filtered for managed hooks in hooks.json using the
literal string `gsd-check-update.js`.  On Windows the PR-introduced
.cmd shim changes the hooks.json command to
`"path/gsd-check-update.cmd"` (no node prefix, .cmd extension), so
those filters matched 0 entries and 24 Windows subtests failed.

Fixes:
- bug-2760-codex-install-defensive.test.cjs (7 filters): change
  `/gsd-check-update\.js/` → `/gsd-check-update/` to match both
  .js (POSIX) and .cmd (Windows) commands.
- bug-3357-codex-legacy-hooks-json-migration.test.cjs (3 filters):
  same `.js` → no-extension change.
- bug-3427-3433-codex-install-shape.test.cjs (2 filters): same fix;
  add explanatory comment to uninstall assertion.
- codex-config.test.cjs (9 filters + 1 exact-command assertion):
  bulk-replace all `hooksJsonCommands.filter(cmd => cmd.includes('gsd-check-update.js'))`
  with `gsd-check-update`; make the `fresh CODEX_HOME` test platform-
  aware — on win32 assert `.cmd` shim path, on POSIX assert the
  existing `"runner" "script.js"` form (#3017).

All four suites pass locally (macOS / darwin).  Windows subtests
verified against the Windows CI failure log patterns.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix(3426): address pr-review-toolkit + codex review findings

- fix(uninstall): add gsd-check-update.cmd to gsdHooks cleanup list so
  the .cmd shim is removed from disk on Windows uninstall (was left as
  orphan artifact — silent failure post-uninstall)
- test(3426): add uninstall test asserting gsd-check-update.cmd is
  deleted from hooks dir after `uninstall(true, 'codex')` (no coverage existed)
- fix(comment): correct JSDoc on buildCodexHookWindowsShimIR — shim
  content is three-line @ECHO OFF/@SETLOCAL/@runner snippet, not bare
  `@node "script.js" %*` as the old comment claimed
- fix(comment): update stale assertion message in codex-config.test.cjs
  L1457 — said "config.toml references it" but the hook is in hooks.json

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>