The standalone Twig archive no longer contains the nodex monorepo installer.
Remove checks for that unrelated installer while retaining all navigation,
token parity and contrast checks in the foundation test.

--- a/scripts/checks/foundation.mjs
+++ b/scripts/checks/foundation.mjs
@@ -1,7 +1,5 @@
 import assert from 'node:assert/strict';
-import { readFile, mkdtemp, mkdir, writeFile, rm, copyFile } from 'node:fs/promises';
-import { tmpdir } from 'node:os';
+import { readFile } from 'node:fs/promises';
 import path from 'node:path';
 import { fileURLToPath, pathToFileURL } from 'node:url';
-import { spawnSync } from 'node:child_process';
 import { isExternalLink, isLocalAsset, isTrustedPage } from '../../main/security.js';
@@ -60,32 +58 @@
-const temp = await mkdtemp(path.join(tmpdir(), 'twig-install-check-'));
-try {
-  await mkdir(path.join(temp, 'modules/desktop'), { recursive: true });
-  await mkdir(path.join(temp, 'modules/docs'), { recursive: true });
-  await mkdir(path.join(temp, 'bin'));
-  const installer = path.join(temp, 'install.mjs');
-  await copyFile(path.join(root, '../../tools/install-modules.js'), installer);
-  await writeFile(path.join(temp, 'modules/desktop/package.json'), JSON.stringify({ nodexInstall: false }));
-  const marker = path.join(temp, 'called');
-  const fakeNpm = path.join(temp, 'bin', process.platform === 'win32' ? 'npm.cmd' : 'npm');
-  await writeFile(fakeNpm, process.platform === 'win32'
-    ? '@echo off\r\necho called>>"%TWIG_INSTALL_MARKER%"\r\n'
-    : '#!/bin/sh\nprintf "called\\n" >> "$TWIG_INSTALL_MARKER"\n', { mode: 0o755 });
-  const run = () => spawnSync(process.execPath, [installer], {
-    cwd: temp, encoding: 'utf8', shell: false,
-    env: { ...process.env, PATH: `${path.join(temp, 'bin')}${path.delimiter}${process.env.PATH}`, TWIG_INSTALL_MARKER: marker }
-  });
-  let result = run();
-  assert.equal(result.status, 0, result.stderr);
-  assert.match(result.stdout, /Skipping desktop: nodexInstall is false/);
-  await assert.rejects(readFile(marker), { code: 'ENOENT' });
-  await mkdir(path.join(temp, 'modules/service'));
-  await writeFile(path.join(temp, 'modules/service/package.json'), '{}');
-  result = run();
-  assert.equal(result.status, 0, result.stderr);
-  assert.equal((await readFile(marker, 'utf8')).trim(), 'called');
-  await writeFile(path.join(temp, 'modules/desktop/package.json'), '{broken');
-  result = run();
-  assert.equal(result.status, 1);
-  assert.match(result.stderr, /Cannot read package.json for desktop/);
-} finally { await rm(temp, { recursive: true, force: true }); }
-console.log('Foundation checks passed: navigation policy, token parity, contrast, installer opt-out/default/error.');
+console.log('Foundation checks passed: navigation policy, token parity, contrast.');