Backend fixes:
- Add eslint.config.js with proper ES6 module configuration
- Add jest.config.js to support ES modules
- Update package.json with @eslint/js dependency
- Configure npm test script with NODE_OPTIONS for ES modules
- Update Jenkinsfile to block deployments on failed lint/tests
This ensures:
1. ESLint works correctly with ES6 modules
2. Jest can run tests with ES6 imports
3. Deployments are blocked if quality checks fail
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
