feat: add comprehensive CLI smoke and exit code tests (bd-2r1)

Complete integration test suite for CLI interface validation:

TEST COVERAGE:
- Info commands: --version, --describe (operator.json), --schema (JSON Schema)
- Exit code verification: 0=RESOLVED, 1=PARTIAL/UNRESOLVED, 2=REFUSAL
- Output routing: JSON to stdout, CSV to stdout, refusals to stderr (CSV mode)
- Error handling: missing files, wrong columns, format mismatches
- Feature validation: witness flags, map-out sidecars, emit modes
- End-to-end pipeline testing with fixture data

VERIFICATION: 14 tests passing with comprehensive coverage
Ready for Phase 2 integration test expansion

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>

Author: Zac