test(js): add JavaScript tracer unit and E2E tests

Add comprehensive test coverage for JavaScript tracing:
- Unit tests for trace parsing (function_calls and legacy schemas)
- Unit tests for replay test generation (Jest and Vitest)
- E2E test for full tracing pipeline with npm dependencies
- Framework detection tests (Jest, Vitest, package.json)

Author: KRRT7

.github/workflows/js-tests.yml

@@ -47,4 +47,5 @@ jobs:
           uv run pytest tests/test_languages/test_vitest_e2e.py -v
           uv run pytest tests/test_languages/test_javascript_e2e.py -v
           uv run pytest tests/test_languages/test_javascript_support.py -v
+          uv run pytest tests/test_languages/test_javascript_tracer.py -v
           uv run pytest tests/code_utils/test_config_js.py -v

packages/codeflash/runtime/trace-runner.js

@@ -378,18 +378,4 @@ function main() {
     }
 }
 
-// Run if executed directly
-if (require.main === module) {
-    main();
-}
-
-// Export for programmatic use
-module.exports = {
-    parseArgs,
-    registerBabel,
-    runScript,
-    runJest,
-    runVitest,
-    runModule,
-    main,
-};
+main();