Changes:
- Add 6 for-in/for-of test cases to js262_manifest.toml
- Promote js262-for-in-loop from known_fail to pass
- Fix HashMap to IndexMap for deterministic property enumeration
- Update expected outputs to match insertion order
Technical:
- Changed JsObjectData.properties from HashMap to IndexMap
- Added indexmap dependency to js_vm/Cargo.toml
- Updated remove() to shift_remove() to preserve order
- All 169 JS262 tests pass, 607 VM tests pass
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>