feat(tests): integrate Vitest for testing framework and add test scripts

- Added Vitest as a dependency for improved testing capabilities.
- Updated package.json with new test scripts for running tests, watching, and coverage reporting.
- Configured ESLint to recognize test runner scripts and included them in the linting process.
- Modified tsconfig.json to include Vitest types for better TypeScript support in tests.

eslint.config.mjs

@@ -18,6 +18,8 @@ const eslintConfig = [
       'out/**',
       'build/**',
       'next-env.d.ts',
+      'scripts/test-runner.js', // Script Node.js qui utilise require() légitimement
+      'scripts/generate-icons-from-jpg.ts', // Script utilitaire avec require()
     ],
   },
 ];