Fix Jest configuration for workspace and testing library setup

- Convert jest.config.js to jest.config.mjs for ES module compatibility
- Add setupFilesAfterEnv: ['@testing-library/jest-dom'] for custom matchers
- Resolves toBeInTheDocument TypeScript errors in test files
- Fixes @testing-library/react import resolution issues
- All JavaScript tests now pass on Node 20/22

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

Co-Authored-By: Claude <[email protected]>

Author: AbanoubGhadban

jest.config.js renamed to jest.config.mjs

@@ -14,6 +14,7 @@ export default {
   }),
   testEnvironment: 'jsdom',
   setupFiles: ['<rootDir>/node_package/tests/jest.setup.js'],
+  setupFilesAfterEnv: ['@testing-library/jest-dom'],
   // React Server Components tests require React 19 and only run with Node version 18 (`newest` in our CI matrix)
   moduleNameMapper:
     nodeVersion < 18