fix: stable-release npm 인증 문제 해결

- NODE_AUTH_TOKEN 환경 변수 추가
- actions/setup-node가 생성한 .npmrc와 호환되도록 수정
- beta-release.yml과 동일한 인증 방식 적용

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: Seungwoo321

.github/workflows/stable-release.yml

@@ -50,4 +50,5 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
         run: npx semantic-release