RESULT: SUCCESS

FILES CHANGED:
- jq_interpreter/architecture.py
- jq_interpreter/diagnostics.py
- jq_interpreter/runtime.py
- jq_interpreter/__init__.py
- tests/test_architecture.py

SUMMARY:
Established explicit module boundaries, evaluation context isolation, and centralized exit-code contracts. All 15 tests and both declared acceptance checks pass. `sources/` was not modified.

BLOCKERS:
- None