- Fix qq-expand in eval.sx: use concat+list instead of append to prevent
nested lists from being flattened during quasiquote expansion
- Update append primitive to match spec ("if x is list, concatenate")
- Rebuild sx_ref.py with quasiquote fix
- Make relations.py self-contained: parse defrelation AST directly
without depending on the evaluator (25/25 tests pass)
- Replace hand-written JSEmitter with js.sx self-hosting bootstrapper
- Guard server-only tests in test-eval.sx with runtime check
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>