RESULT: SUCCESS

FILES CHANGED:
- jq_interpreter/__init__.py
- jq_interpreter/cli.py
- jq_interpreter/errors.py
- jq_interpreter/evaluator.py
- jq_interpreter/parser.py
- tests/test_io_002_diagnostics.py

SUMMARY:
Implemented `debug`, `stderr`, and `halt_error` with channel separation and exit semantics. All 177 tests pass; diagnostics conformance passes with 1 pass, 0 failures, 0 errors.

BLOCKERS:
- None