chore: Use pure OIDC trusted publishing for npm

Remove NPM_TOKEN, rely on GitHub Actions OIDC for authentication.

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

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

.github/workflows/release.yml

@@ -89,8 +89,6 @@ jobs:
         run: |
           cd npm-package
           npm publish --access public --provenance
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
 
   update-homebrew:
     runs-on: ubuntu-latest