fix: add @types/node to devDependencies for CI

Build failed in GitHub Actions because node:fs and process
types were missing. Works locally via parent project's
@types/node but CI has a clean install.

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

Author: dormstern

package-lock.json

@@ -50,6 +50,7 @@
   },
   "devDependencies": {
     "@types/js-yaml": "^4.0.0",
+    "@types/node": "^22.19.11",
     "@types/picomatch": "^3.0.0",
     "typescript": "^5.7.0",
     "vitest": "^3.0.0"