fix(snap-test): also create lib subdirectory in npm global prefix

npm expects a `lib/` subdirectory inside NPM_CONFIG_PREFIX for global
operations like link and outdated -g.

Author: fengmk2

packages/tools/src/snap-test.ts

@@ -113,7 +113,7 @@ export async function snapTest() {
   fs.mkdirSync(tempTmpDir, { recursive: true });
   // Pre-create the npm global prefix directory so tests using npm global
   // operations (link, outdated -g, etc.) don't fail with ENOENT.
-  fs.mkdirSync(path.join(tempTmpDir, 'npm-global-lib-for-snap-tests'));
+  fs.mkdirSync(path.join(tempTmpDir, 'npm-global-lib-for-snap-tests', 'lib'), { recursive: true });
 
   // Clean up stale .node-version and package.json in the system temp directory.
   // vite-plus walks up the directory tree to resolve Node.js versions, so leftover