New test files:
- test-collections.sx (79): list/dict edge cases, interop, equality
- test-scope.sx (48): let/define/set!/closure/letrec/env isolation
Python test runner (hosts/python/tests/run_tests.py):
- Runs all spec tests against bootstrapped sx_ref.py
- Tree-walk evaluator with full primitive env
- Skips CEK/types/strict/continuations without --full
Cross-host fixes (tests now host-neutral):
- cons onto nil: platform-defined (JS: pair, Python: single)
- = on lists: test identity only (JS: shallow, Python: deep)
- str(true): accept "true" or "True"
- (+ "a" 1): platform-defined (JS: coerces, Python: throws)
- min/max: test with two args (Python single-arg expects iterable)
- TCO depth: lowered to 500 (works on both hosts)
- Strict mode tests moved to test-strict.sx (skipped on Python)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Python: bootstrap.py, platform.py, transpiler.sx, boundary_parser.py, tests/
JavaScript: bootstrap.py, cli.py, platform.py, transpiler.sx
Both bootstrappers verified — build from new locations, output to shared/.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
