RESULT: SUCCESS

FILES CHANGED:
- `cmark`
- `parser/__init__.py`
- `parser/blocks.py`
- `parser/inlines.py`
- `renderer/__init__.py`
- `renderer/html.py`
- `full_test.sh`
- `README.md`
- `test_architecture.py`

SUMMARY:
Implemented the two-phase parser, renderer, executable, and conformance-wrapper boundaries. Added deterministic architecture and stdin/stdout contract tests; all 3 focused tests passed.

BLOCKERS:
- None